Vascular and Bodily Duct Treatment Devices and Methods

ABSTRACT

Devices including, but not limited to, a self-expandable member having a proximal end portion and a main body portion. The self-expandable member is movable from a first delivery position to a second placement position, in the first delivery position the expandable member being in an unexpanded position and having a nominal first diameter and in the second position the expandable member being in a radially expanded position and having a second nominal diameter greater than the first nominal diameter for deployment within a vessel or duct of a patient. The expandable member includes a plurality of cell structures with the cell structures in the main body portion extending circumferentially around a longitudinal axis of the expandable member and the cell structures in the proximal end portion extending less than circumferentially around the longitudinal axis of the expandable member to form first and second peripheral rails that vary in width along their lengths.

RELATED APPLICATION

This application claims the benefit to and is a continuation-in-part ofU.S. patent application Ser. No. 13/021,364, filed Feb. 4, 2011, whichis a continuation-in-part of U.S. patent application Ser. No.12/832,857, filed Jul. 8, 2010, which is a a continuation-in-part ofU.S. patent application Ser. No. 12/643,942, filed Dec. 21, 2009, whichis a continuation-in-part of U.S. patent application Ser. No.12/573,676, filed Oct. 5, 2009, which is a continuation-in-part of U.S.patent application Ser. No. 12/499,713, filed Jul. 8, 2009, thedisclosures, teachings and suggestions of all of which beingincorporated herein by this reference as if fully set forth here.

TECHNICAL FIELD

This application relates to devices and methods for treating thevasculature and other ducts within the body.

BACKGROUND

Self-expanding prostheses, such as stents, covered stents, vasculargrafts, flow diverters, and the like have been developed to treat ductswithin the body. Many of the prostheses have been developed to treatblockages within the vasculature and also aneurysms that occur in thebrain. What are needed are improved treatment methods and devices fortreating the vasculature and other body ducts, such as, for example,aneurysms, stenoses, embolic obstructions, and the like.

SUMMARY OF THE DISCLOSURE

In accordance with one implementation a vascular or bodily ducttreatment device is provided that comprises an elongate self-expandablemember movable from a first delivery position to a second placementposition, in the first delivery position the expandable member being inan unexpanded position and having a nominal first diameter and in thesecond position the expandable member being in a radially expandedposition and having a second nominal diameter greater than the firstnominal diameter for deployment within the bodily duct or vasculature ofa patient, the expandable member comprising a plurality of cellstructures, the expandable member having a proximal end portion with aproximal end, a cylindrical main body portion and a distal end portionwith a distal end, the cell structures in the main body portionextending circumferentially around a longitudinal axis of the expandablemember, the cell structures in the proximal and distal end portionsextending less than circumferentially around the longitudinal axis ofthe expandable member, the outer-most cell structures in the proximalend portion having proximal-most linear wall segments that, in atwo-dimensional view, form first and second substantially linear railsegments that each extend from a position at or near the proximal-mostend of the expandable member to a distal position at or near thecylindrical main body portion. In one implementation the self-expandablemember has a longitudinal slit extending along at least a portion of thelength of the self-expandable member between the proximal end and thedistal end.

In accordance with another implementation a kit is provided thatcomprises an elongate flexible wire having a proximal end and a distalend with an elongate self-expandable member coupled to the distal end,the self-expandable member movable from a first delivery position to asecond placement position, in the first delivery position the expandablemember being in an unexpanded position and having a nominal firstdiameter and in the second position the expandable member being in aradially expanded position and having a second nominal diameter greaterthan the first nominal diameter for deployment in the bodily duct orvasculature of a patient, the self-expandable member comprising aplurality of cell structures, the self-expandable member having aproximal end portion with a proximal end, a cylindrical main bodyportion and a distal end portion with a distal end, the cell structuresin the main body portion extending circumferentially around alongitudinal axis of the expandable member, the cell structures in theproximal and distal end portions extending less than circumferentiallyaround the longitudinal axis of the expandable member, the outer-mostcell structures in the proximal end portion having proximal-most linearwall segments that, in a two-dimensional view, form first and secondsubstantially linear rail segments that each extend from a position ator near the proximal-most end of the expandable member to a distalposition at or near the cylindrical main body portion, the elongate wirewith the expandable member having a first length; and a deliverycatheter having a second length and sufficient flexibility to navigatethe vasculature or bodily duct of the patient, the delivery catheterhaving a proximal end, a distal end and an inner lumen, the inner lumenhaving a diameter sufficient to receive the self-expandable member inits unexpanded position and for advancing the unexpanded member from theproximal end to the distal end of the catheter, the second length beingless than the first length to allow distal advancement of theself-expandable member beyond the distal end of the catheter to permitthe expandable member to deploy toward its expanded position, the distalend of the catheter and the self-expandable member configured to permitproximal retraction of the self-expandable member into the lumen of thecatheter when the self-expandable member is partially or fully deployedoutside the distal end of the catheter. In one implementation, theself-expandable member has a longitudinal slit extending along at leasta portion of the length of the self-expandable member between theproximal end and the distal end.

In accordance with one implementation, a bodily duct or vasculartreatment device is provided having an elongate self-expandable membermovable from a first delivery position to a second placement position,in the first delivery position the expandable member being in anunexpanded position and having a nominal first diameter and in thesecond position the expandable member being in a radially expandedposition and having a second nominal diameter greater than the firstnominal diameter for deployment within the bodily duct or vasculature ofa patient, the expandable member comprising a plurality of generallylongitudinal undulating elements with adjacent undulating elements beinginterconnected in a manner to form a plurality of diagonally disposedcell structures, the expandable member having a proximal end portion, acylindrical main body portion and a distal end portion, the cellstructures in the main body portion extending circumferentially around alongitudinal axis of the expandable member, the cell structures in theproximal and distal end portions extending less than circumferentiallyaround the longitudinal axis of the expandable member, the outer-mostcell structures in the proximal end portion having proximal-most linearwall segments that, in a two-dimensional view, form first and secondsubstantially linear rail segments that each extend from a position ator near the proximal-most end of the expandable member to a position ator near the cylindrical main body portion. In one implementation,connected to the proximal-most end of the expandable member is aproximally extending elongate flexible wire having a length andflexibility sufficient for navigating and accessing the vasculature orbodily duct of the patient.

In accordance with another implementation, a vascular treatment deviceis provided that includes an elongate self-expandable member movablefrom a first delivery position to a second placement position, in thefirst delivery position the expandable member being in an unexpandedposition and having a nominal first diameter and in the second positionthe expandable member being in a radially expanded position and having asecond nominal diameter greater than the first nominal diameter fordeployment within the vasculature of a patient, the expandable membercomprising a plurality of generally longitudinal undulating elementswith adjacent undulating elements being interconnected in a manner toform a plurality of cell structures that are arranged to induce twistingof the expandable member as the expandable member transitions from theunexpanded position to the expanded position, the expandable memberhaving a proximal end portion, a cylindrical main body portion and adistal end portion, the cell structures in the main body portionextending circumferentially around a longitudinal axis of the expandablemember, the cell structures in the proximal and distal end portionsextending less than circumferentially around the longitudinal axis ofthe expandable member, the outer-most cell structures in the proximalend portion having proximal-most linear wall segments that form firstand second substantially linear rail segments that each extend from aposition at or near the proximal-most end of the expandable member to aposition at or near the cylindrical main body portion. In oneimplementation, connected to the proximal-most end of the expandablemember is a proximally extending elongate flexible wire having a lengthand flexibility sufficient for navigating and accessing the vasculatureor bodily duct of the patient.

In accordance with another implementation, a bodily duct or vasculartreatment device is provided that includes an elongate self-expandablemember movable from a first delivery position to a second placementposition, in the first delivery position the expandable member being inan unexpanded position and having a nominal first diameter and in thesecond position the expandable member being in a radially expandedposition and having a second nominal diameter greater than the firstnominal diameter for deployment within the bodily duct or vasculature ofa patient, the expandable member comprising a plurality of generallylongitudinal undulating elements with adjacent undulating elements beinginterconnected to form a plurality of diagonally disposed cellstructures, the expandable member having a cylindrical portion and adistal end portion, the cell structures in the cylindrical portionextending circumferentially around a longitudinal axis of the expandablemember, the cell structures in the distal end portion extending lessthan circumferentially around the longitudinal axis of the expandablemember, the proximal-most cell structures in the main body portionhaving proximal-most end points. One or more of the proximal-most endpoints of the expandable member have a proximally extending elongateflexible wire having a length and flexibility sufficient for navigatingand accessing the vasculature or bodily duct of the patient.

In accordance with another implementation, a kit is provided thatincludes an elongate flexible wire having a proximal end and a distalend with an elongate self-expandable member attached to the distal end,the self-expandable member movable from a first delivery position to asecond placement position, in the first delivery position the expandablemember being in an unexpanded position and having a nominal firstdiameter and in the second position the expandable member being in aradially expanded position and having a second nominal diameter greaterthan the first nominal diameter for deployment within a bodily duct orvasculature of a patient, the expandable member comprising a pluralityof generally longitudinal undulating elements with adjacent undulatingelements being interconnected in a manner to form a plurality ofdiagonally disposed cell structures, the expandable member having aproximal end portion, a cylindrical main body portion and a distal endportion, the cell structures in the main body portion extendingcircumferentially around a longitudinal axis of the expandable member,the cell structures in the proximal and distal end portions extendingless than circumferentially around the longitudinal axis of theexpandable member, the outer-most cell structures in the proximal endportion having proximal-most linear wall segments that, in atwo-dimensional view, form first and second substantially linear railsegments that each extend from a position at or near the proximal-mostend of the expandable member to a position at or near the cylindricalmain body portion, the elongate wire and expandable member having afirst length, and a delivery catheter having a second length andsufficient flexibility to navigate the vasculature or bodily duct of apatient, the delivery catheter having a proximal end, a distal end andan inner diameter, the inner diameter sufficient to receive theexpandable member in its unexpanded position and for advancing theunexpanded member from the proximal end to the distal end of thecatheter, the second length being less that the first length to allowdistal advancement of the expandable member beyond the distal end of thecatheter to permit the expandable member to deploy toward its expandedposition, the distal end of the catheter and the expandable memberconfigured to permit proximal retraction of the expandable member intothe catheter when the expandable member is partially or fully deployedoutside the distal end of the catheter.

In accordance with another implementation, a method for removing anembolic obstruction from a vessel of a patient is provided that includes(a) advancing a delivery catheter having an inner lumen with proximalend and a distal end to the site of an embolic obstruction in theintracranial vasculature of a patient so that the distal end of theinner lumen is positioned distal to the embolic obstruction, the innerlumen having a first length, (b) introducing an embolic obstructionretrieval device comprising an elongate flexible wire having a proximalend and a distal end with an elongate self-expandable member attached tothe distal end into the proximal end of the inner lumen of the catheterand advancing the self-expandable member to the distal end of the lumen,the self-expandable member movable from a first delivery position to asecond placement position, in the first delivery position the expandablemember being in an unexpanded position and having a nominal firstdiameter and in the second position the expandable member being in aradially expanded position and having a second nominal diameter greaterthan the first nominal diameter for deployment within an embolicobstruction of a patient, the expandable member comprising a pluralityof generally longitudinal undulating elements with adjacent undulatingelements being interconnected in a manner to form a plurality of cellstructures, the expandable member having a proximal end portion, acylindrical main body portion and a distal end portion, the cellstructures in the main body portion extending circumferentially around alongitudinal axis of the expandable member, the cell structures in theproximal and distal end portions extending less than circumferentiallyaround the longitudinal axis of the expandable member, the outer cellstructures in the proximal end portion having proximal linear wallsegments that, in a two-dimensional view, form first and secondsubstantially linear rail segments that each extend from a position ator near the proximal end of the expandable member to a position at ornear the cylindrical main body portion, the elongate wire and expandablemember in combination having a second length longer than the firstlength, (c) proximally retracting the delivery catheter sufficient todeploy the self-expandable device so that the one or more of the cellstructures entrap at least a portion of the embolic obstruction, and (d)proximally retracting the delivery catheter and self-expandable deviceto outside the patient. In an alternative implementation, theself-expandable member is partially or fully retracted into the innerlumen of the delivery catheter prior to proximally retracting thedelivery catheter and self-expandable device to outside the patient.

In accordance with another implementation, a device is providedcomprising an elongate self-expandable member movable from a firstdelivery position to a second placement position, in the first deliveryposition the expandable member being in an unexpanded position andhaving a nominal first diameter and in the second position theexpandable member being in a radially expanded position and having asecond nominal diameter greater than the first nominal diameter fordeployment within a vessel or duct of a patient, the expandable membercomprising a plurality of cell structures, the expandable member havinga proximal end portion with a proximal end and a cylindrical main bodyportion, the cell structures in the main body portion comprise a firstplurality of intersecting struts and extend circumferentially around alongitudinal axis of the expandable member, the cell structures in theproximal end portion comprise a second plurality of intersecting strutsand extend less than circumferentially around the longitudinal axis ofthe expandable member, at least some of the first plurality ofintersecting struts having a thickness to width ratio of greater thanone.

In accordance with yet another implementation, a device is providedcomprising a delivery wire, an elongate self-expandable member movablefrom a first delivery position to a second placement position, in thefirst delivery position the expandable member being in an unexpandedposition and having a nominal first diameter and in the second positionthe expandable member being in a radially expanded position and having asecond nominal diameter greater than the first nominal diameter fordeployment within a vessel or duct of a patient, the expandable membercomprising a plurality of cell structures, the expandable member havinga proximal end portion with a proximal end and a cylindrical main bodyportion, the proximal end having an integrally formed wire segmentextending therefrom with a coil positioned about the wire segment, thecoil comprising a first closely wound segment and a second loosely woundsegment that contains at least one gap, the cell structures in the mainbody portion extending circumferentially around a longitudinal axis ofthe expandable member, the cell structures in the proximal end portionextending less than circumferentially around the longitudinal axis ofthe expandable member, a proximal end of the wire segment attached to adistal end of the delivery wire by a bonding agent within the secondloosely wound segment of the coil.

In accordance with yet another implementation, a device is providedcomprising an elongate self-expandable member movable from a firstdelivery position to a second placement position, in the first deliveryposition the expandable member being in an unexpanded position andhaving a nominal first diameter and in the second position theexpandable member being in a radially expanded position and having asecond nominal diameter greater than the first nominal diameter fordeployment within a vessel or duct of a patient, the expandable membercomprising a plurality of cell structures, the expandable member havinga proximal end portion with a proximal end and a cylindrical main bodyportion, the cell structures in the main body portion extendingcircumferentially around a longitudinal axis of the expandable member,the cell structures in the proximal end portion extending less thancircumferentially around the longitudinal axis of the expandable member,the cell structures having dimensional and material characteristics thatresult in about a −1.5N to a about a −3.5N overall reduction in radialforce along the length of the expandable member per millimeter ofexpansion during about an initial 0.50 mm diametric range of expansionfrom the nominal diameter and that results in about a −0.10N to about a−0.50N overall reduction in radial force along the length of theexpandable member per millimeter of expansion during subsequentdiametric ranges of expansion. In one implementation the elongateself-expandable member has a designated maximum second nominal diameter,the radial force exerted by the elongate self-expandable member beinggreater than zero when expanded to the maximum second nominal diameter.

In accordance with yet another implementation, a device is providedcomprising an elongate self-expandable member movable from a firstdelivery position to a second placement position, in the first deliveryposition the expandable member being in an unexpanded position andhaving a nominal first diameter and in the second position theexpandable member being in a radially expanded position and having asecond nominal diameter greater than the first nominal diameter fordeployment within the bodily duct or vasculature of a patient, theexpandable member comprising a plurality of generally longitudinalundulating elements with adjacent undulating elements beinginterconnected in a manner to form a plurality of diagonally disposedcell structures, the expandable member having a proximal end portion, acylindrical main body portion and a distal end portion, the cellstructures in the main body portion extending circumferentially around alongitudinal axis of the expandable member, the cell structures in theproximal and distal end portions extending less than circumferentiallyaround the longitudinal axis of the expandable member, the cellstructures in the proximal end portion extending less thancircumferentially around the longitudinal axis of the expandable member,the cell structures having dimensional and material characteristics thatresult in about a −1.5N to a about a −3.5N overall reduction in radialforce along the length of the expandable member per millimeter ofexpansion during about an initial 0.50 mm diametric range of expansionfrom the first nominal diameter and that results in about a −0.10N toabout a −0.50N overall reduction in radial force along the length of theexpandable member per millimeter of expansion during subsequentdiametric ranges of expansion. In one implementation the elongateself-expandable member has a designated maximum second nominal diameter,the radial force exerted by the elongate self-expandable member beinggreater than zero when expanded to the maximum second nominal diameter.

In another implementation a clot retrieval device is providedcomprising: an elongate self-expandable member movable from a firstdelivery position to a second placement position, in the first deliveryposition the expandable member being in an unexpanded position andhaving a nominal first diameter and in the second position theexpandable member being in a radially expanded position and having asecond nominal diameter greater than the first nominal diameter fordeployment within an embolic obstruction of a patient, the expandablemember comprising a plurality of generally longitudinal undulatingelements with adjacent undulating elements being interconnected in amanner to form a plurality of diagonally disposed cell structures, theexpandable member having a proximal end portion and a cylindrical mainbody portion, the cell structures in the main body portion extendingcircumferentially around a longitudinal axis of the expandable member,the cell structures in the proximal end portion extending less thancircumferentially around the longitudinal axis of the expandable memberto form first and second peripheral rails having proximal and distal endsegments, the cell structures in the proximal end portion comprising afirst set of cell structures arranged to form the first peripheral rail,a second set of cell structures arranged to form the second peripheralrail and a third set of cell structures located between the first andsecond set of cell structures, the first and second set of cellstructures having in common a proximal-most cell structure, the cellstructures in the main body portion comprising a fourth set of cellstructures, the proximal-most cell structure and the first set of cellstructures having circumferential outer-most strut members that definethe first peripheral rail, the proximal-most cell structure and thesecond set of cell structures having circumferential outer-most strutmembers that define the second peripheral rail, at least some of thecircumferential outer-most strut members having different widthdimensions and arranged so that the first and second peripheral railsvary between a first width dimension at the proximal end segment tosecond width dimension at the distal end segment, the second widthdimension less than the first width dimension. In one implementation thefirst and second peripheral rails are devoid of undulations and thepercentage change between the first width dimension and second widthdimension is between about 20.0% and about 50.0%.

In another implementations a clot retrieval devices is providedcomprising: an elongate self-expandable member movable from a firstdelivery position to a second placement position, in the first deliveryposition the expandable member being in an unexpanded position andhaving a nominal first diameter and in the second position theexpandable member being in a radially expanded position and having asecond nominal diameter greater than the first nominal diameter fordeployment within an embolic obstruction of a patient, the expandablemember comprising a plurality of generally longitudinal undulatingelements with adjacent undulating elements being interconnected in amanner to form a plurality of diagonally disposed cell structures, theexpandable member having a proximal end portion and a cylindrical mainbody portion, the cell structures in the main body portion extendingcircumferentially around a longitudinal axis of the expandable member,the cell structures in the proximal end portion extending less thancircumferentially around the longitudinal axis of the expandable memberto form first and second peripheral rails having proximal and distal endsegments, the cell structures in the proximal end portion comprising afirst set of cell structures arranged to form the first peripheral rail,a second set of cell structures arranged to form the second peripheralrail and a third set of cell structures located between the first andsecond set of cell structures, the first and second set of cellstructures having in common a proximal-most cell structure, the cellstructures in the main body portion comprising a fourth set of cellstructures, the proximal-most cell structure and the first set of cellstructures having circumferential outer-most strut members that definethe first peripheral rail, the proximal-most cell structure and thesecond set of cell structures having circumferential outer-most strutmembers that define the second peripheral rail, at least some of thecircumferential outer-most strut members having different widthdimensions and arranged so that the first and second peripheral railsvary between a first width dimension at the proximal end segment tosecond width dimension at the distal end segment, the second widthdimension less than the first width dimension, the percentage changebetween the first width dimension and second width dimension is betweenabout 20.0% and about 50.0%, the third set of cell structures comprisingstruts having a third width dimensions less than the second widthdimension, the fourth set of cell structures comprising struts having afourth width dimensions less than the second width dimension, thepercentage difference between the second width dimension and the thirdwidth dimension being between about 10.0% and about 25.0%, thepercentage difference between the second width dimension and the fourthwidth dimension being between about 10.0% and about 25.0%.

In another implementation a clot retrieval device is providedcomprising: an elongate self-expandable member movable from a firstdelivery position to a second placement position, in the first deliveryposition the expandable member being in an unexpanded position andhaving a nominal first diameter and in the second position theexpandable member being in a radially expanded position and having asecond nominal diameter greater than the first nominal diameter fordeployment within an embolic obstruction of a patient, the expandablemember comprising a plurality of generally longitudinal undulatingelements with adjacent undulating elements being interconnected in amanner to form a plurality of diagonally disposed cell structures, theexpandable member having a proximal end portion and a cylindrical mainbody portion, the cell structures in the main body portion extendingcircumferentially around a longitudinal axis of the expandable member,the cell structures in the proximal end portion extending less thancircumferentially around the longitudinal axis of the expandable memberto form first and second peripheral rails having proximal and distal endsegments, the cell structures in the proximal end portion comprising afirst set of cell structures arranged to form the first peripheral rail,a second set of cell structures arranged to form the second peripheralrail and a third set of cell structures located between the first andsecond set of cell structures, the first and second set of cellstructures having in common a proximal-most cell structure, the cellstructures in the main body portion comprising a fourth set of cellstructures, the proximal-most cell structure and the first set of cellstructures having circumferential outer-most strut members that definethe first peripheral rail, the proximal-most cell structure and thesecond set of cell structures having circumferential outer-most strutmembers that define the second peripheral rail, at least some of thecircumferential outer-most strut members having different widthdimensions and arranged so that the first and second peripheral railsvary between a first width dimension at the proximal end segment tosecond width dimension at the distal end segment, the second widthdimension less than the first width dimension, the percentage changebetween the first width dimension and second width dimension is betweenabout 20.0% and about 50.0%, the third set of cell structures comprisingstruts having a third width dimension less than the second widthdimension, the fourth set of cell structures comprising struts having afourth width dimension substantially the same as the second widthdimension, the percentage difference between the second width dimensionand the third width dimension being between about 10.0% and about 25.0%.

In another implementation a clot retrieval device is providedcomprising: an elongate self-expandable member movable from a firstdelivery position to a second placement position, in the first deliveryposition the expandable member being in an unexpanded position andhaving a nominal first diameter and in the second position theexpandable member being in a radially expanded position and having asecond nominal diameter greater than the first nominal diameter fordeployment within an embolic obstruction of a patient, the expandablemember comprising a plurality of generally longitudinal undulatingelements with adjacent undulating elements being interconnected in amanner to form a plurality of diagonally disposed cell structures, theexpandable member having a proximal end portion and a cylindrical mainbody portion, the cell structures in the main body portion extendingcircumferentially around a longitudinal axis of the expandable member,the cell structures in the proximal end portion extending less thancircumferentially around the longitudinal axis of the expandable memberto form first and second peripheral rails having proximal and distal endsegments, the cell structures in the proximal end portion comprising afirst set of cell structures arranged to form the first peripheral rail,a second set of cell structures arranged to form the second peripheralrail and a third set of cell structures located between the first andsecond set of cell structures, the first and second set of cellstructures having in common a proximal-most cell structure, the cellstructures in the main body portion comprising a fourth and fifth set ofcell structures, the proximal-most cell structure and the first set ofcell structures having circumferential outer-most strut members thatdefine the first peripheral rail, the proximal-most cell structure andthe second set of cell structures having circumferential outer-moststrut members that define the second peripheral rail, at least some ofthe circumferential outer-most strut members having different widthdimensions and arranged so that the first and second peripheral railsvary between a first width dimension at the proximal end segment tosecond width dimension at the distal end segment, the second widthdimension less than the first width dimension, the size of the cellstructures in the third and fifth set of cell structures beingsubstantially the same, the size of the cell structures in the fourthset of cell structures being greater than the size of the cellstructures in the third set of cell structures, the cell structures inthe third, fourth and fifth set of cell structures comprising third,fourth and fifth struts, respectively, at least some of the fourth andfifth struts, or segments thereof, having a width dimension that isgreater than the width dimension of the third struts.

In another implementation a clot retrieval device is providedcomprising: an elongate self-expandable member movable from a firstdelivery position to a second placement position, in the first deliveryposition the expandable member being in an unexpanded position andhaving a nominal first diameter and in the second position theexpandable member being in a radially expanded position and having asecond nominal diameter greater than the first nominal diameter fordeployment within an embolic obstruction of a patient, the expandablemember comprising a plurality of generally longitudinal undulatingelements with adjacent undulating elements being interconnected in amanner to form a plurality of diagonally disposed cell structures, theexpandable member having a proximal end portion and a cylindrical mainbody portion, the cell structures in the main body portion extendingcircumferentially around a longitudinal axis of the expandable member,the cell structures in the proximal end portion extending less thancircumferentially around the longitudinal axis of the expandable memberto form first and second peripheral rails having proximal and distal endsegments, the cell structures in the proximal end portion comprising afirst set of cell structures arranged to form the first peripheral rail,a second set of cell structures arranged to form the second peripheralrail and a third set of cell structures located between the first andsecond set of cell structures, the first and second set of cellstructures having in common a proximal-most cell structure, the cellstructures in the main body portion comprising a fourth and fifth set ofcell structures, the proximal-most cell structure and the first set ofcell structures having circumferential outer-most strut members thatdefine the first peripheral rail, the proximal-most cell structure andthe second set of cell structures having circumferential outer-moststrut members that define the second peripheral rail, at least some ofthe circumferential outer-most strut members having different widthdimensions and arranged so that the first and second peripheral railsvary between a first width dimension at the proximal end segment tosecond width dimension at the distal end segment, the second widthdimension less than the first width dimension, the size of the cellstructures in the third and fifth set of cell structures beingsubstantially the same, the size of the cell structures in the fourthset of cell structures being greater than the size of the cellstructures in the third set of cell structures, the cell structures inthe third, fourth and fifth set of cell structures comprising third,fourth and fifth struts, respectively, the width dimension of the thirdstruts being less than the second width dimension, at least some of thefourth and fifth struts, or segments thereof, having a width dimensionsubstantially equal to the second width dimension.

In another implementation a clot retrieval device is providedcomprising: an elongate self-expandable member movable from a firstdelivery position to a second placement position, in the first deliveryposition the expandable member being in an unexpanded position andhaving a nominal first diameter and in the second position theexpandable member being in a radially expanded position and having asecond nominal diameter greater than the first nominal diameter fordeployment within an embolic obstruction of a patient, the expandablemember comprising a plurality of generally longitudinal undulatingelements with adjacent undulating elements being interconnected in amanner to form a plurality of diagonally disposed cell structures, theexpandable member having a proximal end portion, a cylindrical main bodyportion and a distal end portion, the cell structures in the main bodyportion extending circumferentially around a longitudinal axis of theexpandable member, the cell structures in the proximal and distal endportions extending less than circumferentially around the longitudinalaxis of the expandable member, the cell structures in the proximal endportion forming first and second peripheral rails having proximal anddistal end segments, the cell structures in the proximal end portioncomprising a first set of cell structures arranged to form the firstperipheral rail, a second set of cell structures arranged to form thesecond peripheral rail and a third set of cell structures locatedbetween the first and second set of cell structures, the first andsecond set of cell structures having in common a proximal-most cellstructure, the cell structures in the main body portion comprising afourth set of cell structures, the cell structures in the distal endportion comprising a sixth set of cell structures, the proximal-mostcell structure and the first set of cell structures havingcircumferential outer-most strut members that define the firstperipheral rail, the proximal-most cell structure and the second set ofcell structures having circumferential outer-most strut members thatdefine the second peripheral rail, at least some of the circumferentialouter-most strut members having different width dimensions and arrangedso that the first and second peripheral rails vary between a first widthdimension at the proximal end segment to second width dimension at thedistal end segment, the second width dimension less than the first widthdimension. In one implementation the first and second peripheral railsare devoid of undulations and the percentage change between the firstwidth dimension and second width dimension is between about 20.0% andabout 50.0%.

In another implementation a clot retrieval device is providedcomprising: an elongate self-expandable member movable from a firstdelivery position to a second placement position, in the first deliveryposition the expandable member being in an unexpanded position andhaving a nominal first diameter and in the second position theexpandable member being in a radially expanded position and having asecond nominal diameter greater than the first nominal diameter fordeployment within an embolic obstruction of a patient, the expandablemember comprising a plurality of generally longitudinal undulatingelements with adjacent undulating elements being interconnected in amanner to form a plurality of diagonally disposed cell structures, theexpandable member having a proximal end portion, a cylindrical main bodyportion and a distal end portion, the cell structures in the main bodyportion extending circumferentially around a longitudinal axis of theexpandable member, the cell structures in the proximal and distal endportions extending less than circumferentially around the longitudinalaxis of the expandable member, the cell structures in the proximal endportion forming first and second peripheral rails having proximal anddistal end segments, the cell structures in the proximal end portioncomprising a first set of cell structures arranged to form the firstperipheral rail, a second set of cell structures arranged to form thesecond peripheral rail and a third set of cell structures locatedbetween the first and second set of cell structures, the first andsecond set of cell structures having in common a proximal-most cellstructure, the cell structures in the main body portion comprising afourth and fifth set of cell structures, the cell structures in thedistal end portion comprising a sixth set of cell structures, theproximal-most cell structure and the first set of cell structures havingcircumferential outer-most strut members that define the firstperipheral rail, the proximal-most cell structure and the second set ofcell structures having circumferential outer-most strut members thatdefine the second peripheral rail, at least some of the circumferentialouter-most strut members having different width dimensions and arrangedso that the first and second peripheral rails vary between a first widthdimension at the proximal end segment to second width dimension at thedistal end segment, the second width dimension less than the first widthdimension, the size of the cell structures in the third, fifth and sixthset of cell structures being substantially the same, the size of thecell structures in the fourth set of cell structures being greater thanthe size of the cell structures in the third, fifth and sixth set ofcell structures, the cell structures in the third, fourth, fifth andsixth set of cell structures comprising third, fourth, fifth and sixthstruts, respectively, at least some of the fourth and fifth struts, orsegments thereof, having a width dimension that is greater than thewidth dimension of the third and sixth struts.

In another implementation a clot retrieval device is providedcomprising: an elongate self-expandable member movable from a firstdelivery position to a second placement position, in the first deliveryposition the expandable member being in an unexpanded position andhaving a nominal first diameter and in the second position theexpandable member being in a radially expanded position and having asecond nominal diameter greater than the first nominal diameter fordeployment within an embolic obstruction of a patient, the expandablemember comprising a plurality of generally longitudinal undulatingelements with adjacent undulating elements being interconnected in amanner to form a plurality of diagonally disposed cell structures, theexpandable member having a proximal end portion, a cylindrical main bodyportion and a distal end portion, the cell structures in the main bodyportion extending circumferentially around a longitudinal axis of theexpandable member, the cell structures in the proximal and distal endportions extending less than circumferentially around the longitudinalaxis of the expandable member, the cell structures in the proximal endportion forming first and second peripheral rails having proximal anddistal end segments, the cell structures in the proximal end portioncomprising a first set of cell structures arranged to form the firstperipheral rail, a second set of cell structures arranged to form thesecond peripheral rail and a third set of cell structures locatedbetween the first and second set of cell structures, the first andsecond set of cell structures having in common a proximal-most cellstructure, the cell structures in the main body portion comprising afourth and fifth set of cell structures, the cell structures in thedistal end portion comprising a sixth set of cell structures, theproximal-most cell structure and the first set of cell structures havingcircumferential outer-most strut members that define the firstperipheral rail, the proximal-most cell structure and the second set ofcell structures having circumferential outer-most strut members thatdefine the second peripheral rail, at least some of the circumferentialouter-most strut members having different width dimensions and arrangedso that the first and second peripheral rails vary between a first widthdimension at the proximal end segment to second width dimension at thedistal end segment, the second width dimension less than the first widthdimension, the size of the cell structures in the third, fifth and sixthset of cell structures being substantially the same, the size of thecell structures in the fourth set of cell structures being greater thanthe size of the cell structures in the third, fifth and sixth set ofcell structures, the cell structures in the third, fourth, fifth andsixth set of cell structures comprising third, fourth, fifth and sixthstruts, respectively, the width dimension of the third and sixth strutsbeing less than the second width dimension, at least some of the fourthand fifth struts, or segments thereof, having a width dimensionsubstantially equal to the second width dimension.

In other implementations embolic obstruction retrieval devices areprovided comprising; an elongate self-expandable member movable from afirst delivery position to a second placement position, in the firstdelivery position the expandable member being in an unexpanded positionand having a nominal first diameter and in the second position theexpandable member being in a radially expanded position and having asecond nominal diameter greater than the first nominal diameter fordeployment within an embolic obstruction of a patient, the expandablemember comprising a plurality of generally longitudinal undulatingelements with adjacent undulating elements being interconnected in amanner to form a plurality of diagonally disposed cell structures, theexpandable member having a proximal antenna, a proximal end portion anda cylindrical main body portion, the cell structures in the main bodyportion extending circumferentially around a longitudinal axis of theexpandable member, the cell structures in the proximal and distal endportions extending less than circumferentially around the longitudinalaxis of the expandable member, the outer-most cell structures in theproximal end portion having proximal-most wall segments that form firstand second rail segments that each extend from a position at or near theproximal-most end of the expandable member to a position at or near thecylindrical main body portion, the proximal-most cell structure of theproximal end portion comprising first and second outer struts thatextend distally from the proximal antenna, in a two-dimensional layoutat least a portion of each of the first and second outer struts comprisea straight segment, each of the straight segment being coextensive tothe proximal antenna.

In other implementations embolic obstruction retrieval devices areprovided comprising; an elongate self-expandable member movable from afirst delivery position to a second placement position, in the firstdelivery position the expandable member being in an unexpanded positionand having a nominal first diameter and in the second position theexpandable member being in a radially expanded position and having asecond nominal diameter greater than the first nominal diameter fordeployment within an embolic obstruction of a patient, the expandablemember comprising a plurality of generally longitudinal undulatingelements with adjacent undulating elements being interconnected in amanner to form a plurality of diagonally disposed cell structures, theexpandable member having a proximal antenna, a proximal end portion anda cylindrical main body portion, the cell structures in the main bodyportion extending circumferentially around a longitudinal axis of theexpandable member, the cell structures in the proximal and distal endportions extending less than circumferentially around the longitudinalaxis of the expandable member, a first set of outer-most cell structuresin the proximal end portion having proximal-most wall segments that forma non-undulating rail segment that extends from a position at or nearthe proximal-most end of the expandable member to a position at or nearthe cylindrical main body portion, and a second set of outer-most cellstructures in the proximal end portion having proximal-most wallsegments that form an undulating rail segment that extends from aposition at or near the proximal-most end of the expandable member to aposition at or near the cylindrical main body portion.

BRIEF DESCRIPTION OF THE DRAWINGS

Alternative implementations of the present disclosure are describedherein with reference to the drawings wherein:

FIG. 1A illustrates a two-dimensional plane view of an expandable memberof a treatment device in one embodiment.

FIG. 1B is an isometric view of the expandable member illustrated inFIG. 1A

FIG. 2 illustrates a distal wire segment that extends distally from anexpandable member in one embodiment.

FIG. 3 illustrates the distal end of an expandable member having anatraumatic tip.

FIG. 4A illustrates a two-dimensional plane view of an expandable memberof a treatment device in another embodiment.

FIG. 4B is an enlarged view of the proximal-most segment of theexpandable member illustrated in FIG. 4A.

FIG. 5 illustrates a distal end of an expandable member in oneembodiment.

FIG. 6A illustrates a two-dimensional plane view of an expandable memberof a treatment device in another embodiment.

FIG. 6B is an isometric view of the expandable member illustrated inFIG. 6A.

FIG. 7A illustrates a two-dimensional plane view of an expandable memberof a treatment device in another embodiment.

FIG. 7B is an isometric view of the expandable member illustrated inFIG. 7A.

FIG. 7C illustrates a two-dimensional plane view of an expandable memberof a treatment device in another embodiment.

FIG. 8 illustrates a two-dimensional plane view of an expandable memberof a treatment device in another embodiment.

FIG. 9 illustrates an expandable member in an expanded position having abulge or increased diameter portion.

FIG. 10 illustrates a two-dimensional plane view of an expandable memberof a treatment device in another embodiment.

FIG. 11A illustrates a two-dimensional plane view of an expandablemember of a treatment device in one implementation.

FIG. 11B is an isometric view of the expandable member illustrated inFIG. 11A.

FIG. 12 illustrates a two-dimensional plane view of an expandable memberof a treatment device in another implementation.

FIGS. 13A through 13C illustrate a method for retrieving an embolicobstruction in accordance with one implementation.

FIG. 14 illustrates a two-dimensional plane view of an expandable memberof a treatment device in another embodiment.

FIG. 15 illustrates a two-dimensional plane view of an expandable memberof a treatment device in yet another embodiment.

FIG. 16 illustrates an isometric view of an expandable member in anotherembodiment having an internal wire segment.

FIG. 17 illustrates an isometric view of an expandable member in anotherembodiment having an external wire segment.

FIG. 18 illustrates an isometric view of an expandable member in yetanother embodiment having a distal emboli capture device.

FIG. 19 illustrates a two-dimensional plane view of an expandable memberof a treatment device in another embodiment.

FIG. 20 illustrates the expandable member of FIG. 19 having alongitudinal slit.

FIG. 21 illustrates the expandable member of FIG. 19 having a spiralslit.

FIG. 22 illustrates the expandable member of FIG. 19 having a partialspiral slit.

FIG. 23 illustrates a two-dimensional plane view of an expandable memberof a treatment device in another embodiment.

FIG. 24A illustrates a two-dimensional plane view of an expandablemember of a treatment device in yet another embodiment.

FIG. 24B is an isometric view of the expandable member illustrated inFIG. 24A.

FIG. 25 illustrates a manner in which the proximal extending wiresegment of an expandable device is attached to a delivery wire in oneembodiment.

FIG. 26 illustrates a two-dimensional plane view of an expandable memberof a treatment device in yet another embodiment.

FIGS. 27A and 27B illustrate isometric side and top views, respectively,of the expandable member depicted in FIG. 26.

FIGS. 28A and 28B illustrate a proximal wire segment and a distal wiresegment, respectively, of an expandable member in one implementation.

FIG. 29 is a graph representing a radial force curve of an expandablemember according to one implementation.

FIG. 30 illustrates a two-dimensional plane view of clot retrievaldevices according some implementations.

FIG. 31 illustrates a two-dimensional plane view of clot retrievaldevices according some implementations.

FIGS. 32A-C illustrate cell structures according to some of theimplementations of FIG. 31.

FIG. 33A illustrates a two-dimensional plane view of clot retrievaldevices according some implementations.

FIGS. 33B and 33C illustrate top and side isometric views of the deviceillustrated in FIG. 33A.

FIG. 34A illustrates a two-dimensional plane view of clot retrievaldevices according some implementations.

FIGS. 34B and 34C illustrate top and side isometric views of the deviceillustrated in FIG. 34A.

FIG. 35A illustrates a two-dimensional plane view of clot retrievaldevices according some implementations.

FIGS. 35B and 35C illustrate top and side isometric views of the deviceillustrated in FIG. 35A.

FIG. 36 illustrates a two-dimensional plane view of clot retrievaldevices according some implementations.

FIG. 37 illustrates a two-dimensional plane view of clot retrievaldevices according some implementations.

FIG. 38 illustrates a two-dimensional plane view of clot retrievaldevices according some implementations.

FIG. 39 illustrates a two-dimensional plane view of clot retrievaldevices according some implementations.

FIG. 40A illustrates a two-dimensional plane view of a clot retrievaldevice according to one implementation.

FIG. 40B illustrates a three-dimensional view of the clot retrievaldevice of FIG. 40A.

FIG. 41 illustrates a two-dimensional plane view of clot retrievaldevices according some implementations.

FIG. 42A illustrates a two-dimensional plane view of clot retrievaldevices according some implementations.

FIG. 42B illustrates an enlarged two-dimensional plane view of theproximal tapered end portion of the retriever device depicted in FIG.45A.

FIG. 43 illustrates a two-dimensional plane view of a proximal-most cellstructure according some implementations.

FIG. 44 illustrates a two-dimensional plane view of a proximal-most cellstructure according some implementations.

FIGS. 45A-C illustrate two-dimensional plane views of clot retrievaldevices according some implementations.

FIG. 46 illustrates a two-dimensional plane view of clot retrievaldevices according some implementations.

FIG. 47A illustrates a two-dimensional plane view of a distal end ofclot retrieval devices according some implementations.

FIG. 47B illustrates a three-dimensional view of the distal end depictedin FIG. 47A.

FIG. 48A illustrates a two-dimensional plane view of clot retrievaldevices according some implementations.

FIG. 48B illustrates a three-dimensional view of the clot retrievaldevice depicted in FIG. 48A.

FIG. 49 illustrates a two-dimensional plane view of clot retrievaldevices according some implementations.

DETAILED DESCRIPTION

FIGS. 1A and 1B illustrate a vascular or bodily duct treatment device 10in accordance with one embodiment of the present invention. Device 10 isparticularly suited for accessing and treating the intracranial vascularof a patient, such as for example treating aneurysms or capturing andremoving embolic obstructions. It is appreciated however, that device 10may be used for accessing and treating other locations within thevasculature and also other bodily ducts. Other uses include, forexample, treating stenoses and other types of vascular diseases andabnormalities. FIG. 1A depicts device 10 in a two-dimensional plane viewas if the device were cut and laid flat on a surface. FIG. 1B depictsthe device in its manufactured and/or expanded tubular configuration.Device 10 includes a self-expandable member 12 that is attached orotherwise coupled to an elongate flexible wire 40 that extendsproximally from the expandable member 12. In one embodiment, theexpandable member 12 is made of shape memory material, such as Nitinol,and is preferably laser cut from a tube. In one embodiment, theexpandable member 12 has an integrally formed proximally extending wiresegment 42 that is used to join the elongate flexible wire 40 to theexpandable member 12. In such an embodiment, flexible wire 40 may bejoined to wire segment 42 by the use of solder, a weld, an adhesive, orother known attachment method. In an alternative embodiment, the distalend of flexible wire 40 is attached directly to a proximal end 20 of theexpandable member 12. In one embodiment, the distal end of wire 40 has aflat profile with a width of about 0.005 inches with the width andthickness of the wire segment 42 being about 0.0063 and about 0.0035inches, respectively.

In one embodiment, the distal end of wire 40 is attached to theproximally extending wire segment 42 by the following method, resultingin the joint illustrated in FIG. 25. In one implementation, a coil 41 ispositioned over wire segment 42, the coil having a closely wrappedsegment 41 a abutting the proximal end of expandable member 12, and aloosely wrapped segment 41 b that includes one or more gaps 41 c. Thesize of the one or more gaps 41 c being sufficient to introduce abonding agent into at least the inner cavity of coil segment 41 b. Inone embodiment, the length of wire segment 42 and the coil 41 are equal.In one embodiment the length of the wire segment 42 is 4.0 millimeterswith the coil 41 being of equal length. Once the coil 41 has been placedover the wire segment 42, the distal end of wire 40 is placed withincoil segment 41 b so that it makes contact with and overlaps theproximal end portion of wire segment 42. A bonding agent is then appliedthrough the gaps 41 c of coil 41 to bond the wire 40 with wire segment41. The bonding agent may be an adhesive, solder, or any other suitablebonding agent. When the bonding agent is a solder, a preceding step inthe process involves coating the distal end portion of wire 40 and theproximal end portion of wire segment 42 with tin or another suitablewetting agent. In one implementation the solder is gold and is used toenhance the radiopacity of the joint so that the joint may serve as aproximal radiopaque marker. In addition to the use of gold, all orportions of the coil may be made of a radiopaque material to furtherenhance the radiopacity of the joint. According to one embodiment, thelength of overlap between the wire 40 and wire segment 42 is between0.75 and 1.0 millimeters. In the same implementation or in otherimplementations, the length of coil segment 41 b is equal, orsubstantially equal, to the overlap length of the wire 40 and wiresegment 42. In an alternative embodiment, in lieu of the use of a singlecoil 41, two or more coils in abutting relationship are used with, forexample, a first closely wound coil abutting the proximal end 20 of theexpandable member 12 and a second loosely wound coil with gaps situatedproximal to the closely wound coil. Although not shown in the figures,in one embodiment a distal end length of wire 40 is tapers in the distaldirection from a nominal diameter to a reduced profile. Along thislength is provided a distal wire coil of a constant outer diameter withno taper. In accordance with one implementation, the diameter of coil 41has the same outer diameter as the distal wire coil.

One advantage of the joint construction is that it is resistant tobuckling while the device is being pushed through a delivery catheterwhile at the same time being sufficiently flexible to enable the deviceto be delivered through the tortuous anatomy of a patient. In addition,the joint is able to withstand high tensile and torque loads withoutbreaking. Load test have shown the joint of the previously describedembodiment can withstand in excess of 2 pounds of tensile stress. In oneembodiment, coil 41 is made of a radiopaque material to also function asa proximal radiopaque marker.

FIG. 28A depicts an alternative proximal wire segment construction. Asshown, the proximal wire segment 4002 comprises a first section 4002 aand a second section 4002 b, with the second section 4002 b having awidth W greater than the width of the first section. In oneimplementation a tapered transition section 4003 joins the first andsecond sections 4002 a and 4002 b. In one implementation the width ofthe first section 4002 a is about 0.0063 inches while the width W of thesecond section is between about 0.0085 inches and about 0.0105 inches.In one implementation the length L between the proximal end 4005 of theexpandable member 4004 and second section 4002 b of the wire segment4002 is between about 0.017 inches and about 0.022 inches. An advantageof the inclusion of the second section 4002 b is that the greater widthdimension provides a larger surface area for bonding the wire segment4002 to the elongate wire 40 used in the delivery and retraction of theelongate member from a duct of a patient. In one implementation thefirst section 4002 a has a circular or substantially circularconstruction and the second section 4002 b has a flat profile formed bya pressing/coining operation.

In the embodiment of FIGS. 1A and 1B, expandable member 12 includes aplurality of generally longitudinal undulating elements 24 with adjacentundulating elements being out-of-phase with one another and connected ina manner to form a plurality of diagonally disposed cell structures 26.The expandable member 12 includes a proximal end portion 14, acylindrical main body portion 16 and a distal end portion 18 with thecell structures 26 in the main body portion 16 extending continuouslyand circumferentially around a longitudinal axis 30 of the expandablemember 12. The cell structures 26 in the proximal end portion 14 anddistal end portion 18 extend less than circumferentially around thelongitudinal axis 30 of the expandable member 12.

In one embodiment, expandable member 12 has an overall length of about33.0 millimeters with the main body portion 16 measuring about 16.0millimeters in length and the proximal and distal end portions 14 and 18each measuring about 7.0 millimeters in length. In alternativeembodiments, the length of the main body portion 16 is generally betweenabout 2.5 to about 3.5 times greater than the length of the proximal anddistal end portions 14 and 18.

In use, expandable member 12 is advanced through the tortuous vascularanatomy or bodily duct of a patient to a treatment site in an unexpandedor compressed state (not shown) of a first nominal diameter and ismovable from the unexpanded state to a radially expanded state of asecond nominal diameter greater than the first nominal diameter fordeployment at the treatment site. In alternative exemplary embodimentsthe first nominal diameter (e.g., average diameter of main body portion16) ranges between about 0.017 to about 0.030 inches, whereas the secondnominal diameter (e.g., average diameter of main body portion 16) isbetween about 2.5 to about 5.0 millimeters. In one implementation, thedimensional and material characteristics of the cell structures 26residing in the main body portion 16 of the expandable material 12 areselected to produce sufficient radial force and contact interaction tocause the cell structures 26 to engage with an embolic obstructionresiding in the vascular in a manner that permits partial or fullremoval of the embolic obstruction from the patient. In alternativeembodiments the dimensional and material characteristics of the cellstructures 26 in the main body portion 16 are selected to produce aradial force per unit length of between about 0.005 N/mm to about 0.050N/mm, preferable between about 0.010 N/mm to about 0.050 N/mm, and morepreferably between about 0.030 N/mm and about 0.050 N/mm. In oneembodiment, the diameter of the main body portion 16 in a fully expandedstate is about 4.0 millimeters with the cell pattern, strut dimensionsand material being selected to produce a radial force of between about0.040 N/mm to about 0.050 N/mm when the diameter of the main bodyportion is reduced to between about 1.0 millimeters to about 1.5millimeters. In the same or alternative embodiment, the cell pattern,strut dimensions and material(s) are selected to produce a radial forceof between about 0.010 N/mm to about 0.020 N/mm when the diameter of themain body portion is reduced to 3.0 millimeters.

In the embodiments of FIGS. 1A and 1B, each of the cell structures 26are shown having the same dimensions with each cell structure includinga pair of short struts 32 and a pair of long struts 34. In an exemplaryembodiment, struts 32 have a length of between about 0.080 and about0.100 inches, struts 34 have a length of between about 0.130 and about0.140 inches, with each of struts 32 and 34 having an as-cut width andthickness of about 0.003 inches and about 0.0045 inches, respectively,and a post-polishing width and thickness of between about 0.0022 inchesand about 0.0039 inches, respectively. An advantage of having a strutthickness to width ratio of greater than one is that it promotesintegration of the strut into the embolic obstruction. In alternativeembodiments, the post-polishing width and thickness dimensions variesbetween about 0.0020 inches to about 0.0035 and about 0.0030 inches toabout 0.0040 inches, respectively, with the thickness to width ratiovarying between about 1.0 to about 2.0, and preferably between about1.25 to about 1.75.

In one embodiment, only the strut elements of the main body portion 16have a thickness to width dimension ratio of greater than one. Inanother embodiment, only the strut elements of the main body portion 16and distal end portion 18 have a thickness to width dimension ratio ofgreater than one. In another embodiment, only a portion of the strutelements have a thickness to width dimension ratio of greater than one.In yet another embodiment, strut elements in different parts of theexpandable member have different thickness to width dimension ratios,the ratios in each of the parts being greater than one. As an example,because the radial force exerted by the proximal end portion 14 anddistal end portion 18 of the expandable member 12 may generally be lessthan the radial force exerted by the main body portion 16, the strutelements in the distal and/or proximal end portions can have a thicknessto width ratio that is greater than the thickness to width ratio of thestruts in the main body portion 16. An advantage of this construction isthat the ability of the expandable member 12 to integrate into anembolic obstruction is made to be more uniform along the length of theexpandable member.

In other embodiments, certain, or all of the strut elements have atapered shape with the outer face of the strut having a width dimensionless than the width dimension of the inner face of the strut. In otherembodiments, the expandable member 12 may comprise strut elements havinga generally rectangular cross-section and also strut elements having atapered shape.

It is important to note that the present invention is not limited toexpandable members 12 having uniform cell structures nor to anyparticular dimensional characteristics. As an example, in alternativeembodiments the cell structures 26 in the proximal and/or distal endportions 14 and 18 are either larger or smaller in size than the cellstructures 26 in the main body portion 16. In one embodiment, the cellstructures 26 in the proximal and distal end portions 14 and 18 aresized larger than those in the main body portion 16 so that the radialforces exerted in the end portions 14 and 18 are lower than the radialforces exerted in the main body portion 16.

The radial strength along the length of the expandable member 12 may bevaried in a variety of ways. One method is to vary the mass (e.g., widthand/or thickness) of the struts along the length of the expandablemember 12. Another method is to vary the size of the cell structures 26along the length of the expandable member 12. The use of smaller cellstructures will generally provide higher radial forces than those thatare larger. Varying the radial force exerted along the length of theexpandable member can be particularly advantageous for use in entrappingand retrieving embolic obstructions. For example, in one embodiment theradial force in the distal section of the main body portion 16 of theexpandable member 12 in its expanded state is made to be greater thanthe radial force in the proximal section of the main body portion 16.Such a configuration promotes a larger radial expansion of the distalsection of the main body portion 16 into the embolic obstruction ascompared to the proximal section. Because the expandable member 12 ispulled proximally during the removal of the embolic obstruction from thepatient, the aforementioned configuration will reduce the likelihood ofparticles dislodging from the embolic obstruction during its removal. Inan alternative embodiment the radial force in the proximal section ofthe main body portion 16 of the expandable member 12 in its expandedstate is made to be greater than the radial force in the distal sectionof the main body portion 16. In yet another embodiment, the main bodyportion 16 of the expandable member 12 includes a proximal section, amidsection and a distal section with the radial force in the proximaland distal sections being larger than the radial force in the midsectionwhen the expandable member 12 is in an expanded state.

In alternative embodiments, as exemplified in FIG. 9, the main bodyportion 16 may include an increased diameter portion or bulge 70 toenhance the expandable member's ability to entrap or otherwise engagewith an embolic obstruction. In FIG. 9, a single increased diameterportion 70 is provided within the midsection of main body portion 16. Inalternative embodiments, the increased diameter portion 70 may bepositioned proximally or distally to the midsection. In yet otherembodiments, two or more increased diameter portions 70 may be providedalong the length of the main body portion 16. In one implementation, thetwo or more increased diameter portions 70 have essentially the samemanufactured nominal diameter. In another implementation, thedistal-most increased diameter portion 70 has a greater manufacturednominal diameter than the proximally disposed increased diameterportions. In alternative exemplary embodiments the nominal diameter ofthe increased diameter portion 70 is between about 25.0 to about 45.0percent greater than the nominal diameter of the main body portion. Forexample, in one embodiment, the nominal expanded diameter of main bodyportion 16 is about 3.0 millimeters and the nominal diameter of theincreased diameter portion 70 is about 4.0 millimeters. In anotherembodiment the nominal expanded diameter of main body portion 16 isabout 3.50 millimeters and the nominal diameter of the increaseddiameter portion 70 is about 5.00 millimeters. In one embodiment, theone or more increased diameter portions 70 are formed by placing anexpandable mandrel into the internal lumen of the main body portion 16and expanding the mandrel to create the increased diameter portion 70 ofa desired diameter. In another embodiment, one or more of the increaseddiameter portions 70 are formed by placing a mandrel of a given widthand diameter into the main body portion 16 and then crimping theexpandable member 12 in a manner to cause at least a portion of the mainbody portion 16 to be urged against the mandrel.

In one embodiment, the strut elements in the increased diameter portionor portions 70 have a thickness dimension to width dimension ratio thatis greater than the thickness to width ratio of the other struts in themain body portion 16. In yet another embodiment, the strut elements inthe increased diameter portion or portions 70 have a thickness dimensionto width dimension ratio that is less than the thickness to width ratioof the other struts in the main body portion 16.

In one implementation, a distal wire segment 50, that is attached to orintegrally formed with expandable member 12, extends distally from thedistal end 22 of the expandable member 12 and is configured to assist inguiding the delivery of the expandable member to the treatment site of apatient. FIG. 2 shows a distal wire segment 50 in one embodiment havinga first section 52 of a uniform cross-section and a second section 54having a distally tapering cross-section. In an exemplary embodiment,the first section 52 has a length of about 3.0 millimeters and an as-cutcross-sectional dimension of about 0.0045 inches by about 0.003 inches,and whereas the second section 54 has a length of about 4.0 millimetersand tapers to a distal-most, as-cut, cross-sectional dimension of about0.002 inches by about 0.003 inches. Post-polishing of the devicegenerally involves an etching process that typically results in a 40% to50% reduction in the as-cut cross-sectional dimensions. In anotherembodiment, as depicted in FIG. 3, the distal wire segment 50 is boundby a spring member 57 of a uniform diameter and is equipped with anatraumatic distal tip 58. In alternative embodiments, the spring element57 and/or the atraumatic tip 58 are made or coated with of a radiopaquematerial, such as, for example, platinum.

FIG. 28 b illustrates an alternative distal wire segment construction.As depicted, the distal wire segment 4010 includes a first section 4011a and a second section 4011 b, the second section 4011 b having a widthW greater than the width of the first section 4011 a. In oneimplementation a tapered transition section 4012 joins the first andsecond sections 4011 a and 4011 b. In one implementation the width W ofthe second section is between about 0.003 inches and about 0.004 incheswith the length L between the distal end 4013 of the expandable member4014 and the second section 4011 b of the wire segment 4010 beingbetween about 0.015 inches and about 0.020 inches. An advantage of theinclusion of the second section 4011 b is that the greater widthdimension provides a larger surface area for bonding a coil/springsegment 57 to the wire segment 4010. In one implementation the firstsection 4011 a has a circular or substantially circular construction andthe second section 4011 b has a flat profile formed by apressing/coining operation.

In one embodiment, as will be described in more detail below, theexpandable member 12 is delivered to the treatment site of a patientthrough the lumen of a delivery catheter that has been previously placedat the treatment site. In an alternative embodiment, the vasculartreatment device 10 includes a sheath that restrains the expandablemember 12 in a compressed state during delivery to the treatment siteand which is proximally retractable to cause the expandable member 12 toassume an expanded state.

In one implementation, the expandable member 12 in the expanded state isable to engage an embolic obstruction residing at the treatment site,for example by embedding itself into the obstruction, and is removablefrom the patient by pulling on a portion of the elongate flexible wire40 residing outside the patient until the expandable member 12 and atleast a portion of the embolic obstruction are removed from the patient.

The use of interconnected and out-of-phase undulating elements 24 tocreate at least some of the cell structures 26 in alternativeembodiments provides several advantages. First, the curvilinear natureof the cell structures 26 enhances the flexibility of the expandablemember 12 during its delivery through the tortuous anatomy of thepatient to the treatment site. In addition, the out-of-phaserelationship between the undulating elements facilitates a more compactnesting of the expandable member elements permitting the expandablemember 12 to achieve a very small compressed diameter. A particularadvantage of the expandable member strut pattern shown in FIG. 1A, andvarious other embodiments described herein, is that they enablesequential nesting of the expandable member elements which permit theexpandable members to be partially or fully deployed and subsequentlywithdrawn into the lumen of a delivery catheter. The out-of-phaserelationship also results in a diagonal orientation of the cellstructures 26 which may induce a twisting action as the expandablemember 12 transitions between the compressed state and the expandedstate that helps the expandable member to better engage with the embolicobstruction. In alternative embodiments, the cell structures 26 of theexpandable member 12 are specifically arranged to produce a desiredtwisting action during expansion of the expandable member 12. In thismanner, different expandable members each having different degrees oftwisting action may be made available to treat, for example, differenttypes of embolic obstructions.

To enhance visibility of the device under fluoroscopy, the expandablemember may be fully or partially coated with a radiopaque material, suchas tungsten, platinum, platinum/iridium, tantalum and gold.Alternatively, or in conjunction with the use of a radiopaque coating,radiopaque markers 60 may be positioned at or near the proximal anddistal ends 20 and 22 of the expandable device and/or along the proximaland distal wire segments 42 and 50 and/or on selected expandable memberstrut segments. In one embodiment, the radiopaque markers 60 areradiopaque coils, such as platinum coils.

FIG. 4A depicts a vascular treatment device 100 in a two-dimensionalplane view in another embodiment of the present invention. In itsmanufactured and/or expanded tubular configuration, device 100 has asimilar construction as device 10 shown in FIG. 1B. Like device 10described above in conjunction with FIGS. 1A and 1B, device 100 includesa self-expandable member 112 that is coupled to an elongate flexiblewire 140. The expandable member 112 includes a proximal end portion 114,a cylindrical main body portion 116 and a distal end portion 118. Asmentioned above, delivery of the expandable member 112 in its unexpandedstate to the treatment site of a patient is accomplished in one mannerby placing the expandable member 112 into the proximal end of a deliverycatheter and pushing the expandable member 112 through the lumen of thedelivery catheter until it reaches a distal end of the catheter that hasbeen previously placed at or across the treatment site. The proximallyextending elongate flexible wire 140 which is attached to or coupled tothe proximal end 120 of the expandable member 112 is designed totransmit a pushing force applied to it to its connection point with theelongate flexible member 112. As shown in FIG. 4A, and in more detail inFIG. 4B, device 100 is distinguishable from the various embodiments ofdevice 10 described above in that the proximal-most cell structures 128and 130 in the proximal end portion 114 include strut elements having awidth dimension W1 larger than the width dimension W2 of the other strutelements within the expandable member 112. As shown, the proximal-mostwall sections 160, 162 and 164 of cell structures 128 are made of strutshaving width W1. Moreover, all the struts of the proximal-most cellstructure 130 have an enhanced width W1. The inclusion and placement ofthe struts with width W1 provides several advantages. One advantage isthat they permit the push force applied by the distal end of theelongate wire 140 to the proximal end 120 of elongate member 112 to bemore evenly distributed about the circumference of the expandable member112 as it is being advanced through the tortuous anatomy of a patient.The more evenly distributed push force minimizes the formation oflocalized high force components that would otherwise act on individualor multiple strut elements within the expandable member 112 to causethem to buckle. Also, by including the struts of width W1 in theperipheral regions of proximal end portion 114, they greatly inhibit thetendency of the proximal end portion 114 to buckle under the push forceapplied to it by elongate wire 140. In one exemplary embodiment theas-cut width dimension W1 is about 0.0045 inches and the as-cut widthdimension W2 is about 0.003 inches. As discussed above, post-polishingof the device generally involves an etching process that typicallyresults in a 40% to 50% reduction in the as-cut cross-sectionaldimensions.

It is important to note that although the width dimension W1 is shown asbeing the same among all struts having an enhanced width, this is notrequired. For example, in one embodiment wall segments 158 may have anenhanced width dimension greater than the enhanced width dimension ofwall segments 160, and wall segments 160 may have an enhanced widthdimension greater than the enhanced width dimension of wall segments162, and so on. Moreover, the inner strut elements 166 of theproximal-most cell structure 130 may have an enhanced width dimensionless than the enhanced width dimensions of struts 158. Also, inalternative embodiments, the radial thickness dimension of struts 158,160, 162, 164, etc. may be enhanced in lieu of the width dimension or incombination thereof.

In yet another embodiment, as shown in FIG. 5, some of the strutelements 180 in the distal end portion 118 of the expandable member 112have a mass greater than that of the other struts to resist buckling andpossible breaking of the struts as device 100 is advanced to a treatmentsite of a patient. In the embodiment shown, struts 180 are dimensionedto have the same width as distal wire segment 150. In alternativeembodiments, the thickness dimension of struts 180 may be enhanced inlieu of the width dimension or in combination thereof.

FIGS. 6A and 6B illustrate a vascular treatment device 200 in accordancewith another embodiment of the present invention. FIG. 6A depicts device200 in a two-dimensional plane view as if the device were cut and laidflat on a surface. FIG. 6B depicts the device in its manufactured and/orexpanded tubular configuration. Device 200 includes an expandable member212 having a proximal end portion 214, a cylindrical main body portion216 and a distal end portion 218 with an elongate flexible wire 240attached to or otherwise coupled to the proximal end 220 of theexpandable member. The construction of device 200 is similar to device100 described above in conjunction with FIG. 4A except that the proximalwall segments 260 of cell structures 228 and 230 comprise linear orsubstantially linear strut elements as viewed in the two dimension planeview of FIG. 6A. In one embodiment, the linear strut elements 260 arealigned to form continuous and substantially linear rail segments 270that extend from the proximal end 220 of proximal end portion 214 to aproximal-most end of main body portion 216 (again, as viewed in the twodimension plane view of FIG. 6A) and preferably are of the same length,but may be of different lengths. When the pattern of FIG. 6A is appliedto laser cutting a tubular structure, the resulting expandable memberconfiguration is that as shown in FIG. 6B. As shown in FIG. 6B, railsegments 270 are not in fact linear but are of a curved andnon-undulating shape. This configuration advantageously provides railsegments 270 devoid of undulations thereby enhancing the rail segments'ability to distribute forces and resist buckling when a push force isapplied to them. In alternative preferred embodiments, the angle θbetween the wire segment 240 and rail segments 270 ranges between about140 degrees to about 150 degrees. In one embodiment, one or both of thelinear rail segments 270 have a width dimension W1 which is greater thanthe width dimension of the adjacent strut segments of cell structures228 and 230. An enhanced width dimension W1 of one or both the linearrail segments 270 further enhances the rail segments' ability todistribute forces and resist buckling when a push force is applied tothem. In another implementation, one or both of the linear rail segments270 are provided with an enhanced thickness dimension, rather than anenhanced width dimension to achieve the same or similar result. In yetan alternative implementation, both the width and thickness dimensionsof one or both of the linear rail segments 270 are enhanced to achievethe same or similar results. In yet another implementation, the widthand/or thickness dimensions of each of the rail segments 270 differ in amanner that causes a more even compression of the proximal end portion214 of the expandable member 212 when it is loaded or retrieved into adelivery catheter or sheath (not shown).

FIGS. 7A and 7B illustrate a vascular treatment device 300 in accordancewith another embodiment of the present invention. FIG. 7A depicts device300 in a two-dimensional plane view as if the device were cut and laidflat on a surface. FIG. 7B depicts the device in its manufactured and/orexpanded tubular configuration. Device 300 includes an expandable member312 having a proximal end portion 314, a cylindrical main body portion316 and a distal end portion 318 with an elongate flexible wire 340attached to or otherwise coupled to the proximal end 320 of theexpandable member. The construction of device 300 is similar to device200 described above in conjunction with FIGS. 6A and 6B except that theproximal-most cell structure 330 comprises a substantially diamond shapeas viewed in the two-dimensional plane of FIG. 7A. The substantiallydiamond-shaped cell structure includes a pair of outer strut elements358 and a pair of inner strut elements 360, each having an enhancedwidth and/or enhanced thickness dimension as previously discussed inconjunction with the embodiments of FIGS. 4 and 6. In alternativepreferred embodiments, the inner strut elements 360 intersect the outerstrut elements 358 at an angle β between about 25.0 degrees to about45.0 degrees as viewed in the two-dimensional plane view of FIG. 7A.Maintaining the angular orientation between the inner and outer strutswithin in this range enhances the pushability of the expandable member312 without the occurrence of buckling and without substantiallyaffecting the expandable member's ability to assume a very smallcompressed diameter during delivery.

In one embodiment, the inner strut elements 360 have a mass less thanthat of the outer strut elements 358 that enables them to more easilybend as the expandable member 312 transitions from an expanded state toa compressed state. This assists in achieving a very small compresseddiameter. In another embodiment, as shown in FIG. 7C, the inner strutelements 360 are coupled to the outer strut elements 358 by curvedelements 361 that enable the inner strut elements 360 to more easilyflex when the expandable member 312 is compressed to its deliveryposition.

FIG. 8 illustrates an alternative embodiment of a vascular treatmentdevice 400. Device 400 has a similar construction to that of device 200depicted in FIGS. 6A and 6B with the exception that the expandablemember 412 of device 400 is connected at its proximal end portion 414with two distally extending elongate flexible wires 440 and 441. Asillustrated, wire 440 is attached to or otherwise coupled to theproximal-most end 420 of proximal end portion 414, while wire 441 isattached to or otherwise coupled to the distal-most end 422 of theproximal end portion 414 at the junction with rail segment 470. In yetanother embodiment, an additional elongate flexible wire (not shown) maybe attached to the distal-most end 424. The use of two or more elongateflexible wires 440 and 441 to provide pushing forces to the proximal endportion 414 of elongate member 412 advantageously distributes thepushing force applied to the proximal end portion 414 to more than oneattachment point.

FIG. 10 illustrates a two-dimensional plane view of a vascular treatmentdevice 500 in another embodiment of the present invention. In theembodiment of FIG. 10, expandable member 512 includes a plurality ofgenerally longitudinal undulating elements 524 with adjacent undulatingelements being out-of-phase with one another and connected in a mannerto form a plurality of diagonally disposed cell structures 526. Theexpandable member 512 includes a cylindrical portion 516 and a distalend portion 518 with the cell structures 526 in the main body portion516 extending continuously and circumferentially around a longitudinalaxis 530 of the expandable member 512. The cell structures 526 in thedistal end portion 518 extend less than circumferentially around thelongitudinal axis 530 of the expandable member 512. Attached to orotherwise coupled to each of the proximal-most cell structures 528 areproximally extending elongate flexible wires 540. The use of multipleelongate flexible wires 540 enables the pushing force applied to theproximal end of the expandable member 512 to be more evenly distributedabout its proximal circumference. In another embodiment, although notshown in FIG. 10, the proximal-most strut elements 528 have a widthand/or thickness greater than the struts in the other portions of theexpandable member 512. Such a feature further contributes to the pushforce being evenly distributed about the circumference of the expandablemember 512 and also inhibits the strut elements directly receiving thepush force from buckling.

FIGS. 11A and 11B illustrate a vascular treatment device 600 inaccordance with another embodiment of the present invention. FIG. 11Adepicts device 600 in a two-dimensional plane view as if the device werecut and laid flat on a surface. FIG. 11B depicts the device in itsmanufactured and/or expanded tubular configuration. In the embodiment ofFIGS. 11A and 11B, expandable member 612 includes a plurality ofgenerally longitudinal undulating elements 624 with adjacent undulatingelements being interconnected by a plurality of curved connectors 628 toform a plurality of closed-cell structures 626 disposed about the lengthof the expandable member 612. In the embodiment shown, the expandablemember 612 includes a proximal end portion 614 and a cylindrical portion616 with the cell structures 626 in the cylindrical portion 616extending continuously and circumferentially around a longitudinal axis630 of the expandable member 612. The cell structures 626 in theproximal end portion 614 extend less than circumferentially around thelongitudinal axis 630 of the expandable member 612. In an alternativeembodiment, the expandable member 612 includes a proximal end portion, acylindrical main body portion and a distal end portion, much like theexpandable member 12 depicted in FIGS. 1A and 1B. In such an embodiment,the cell structures 626 in the distal end portion of the expandablemember would extend less than circumferentially around the longitudinalaxis 630 of the expandable member 612 in a manner similar to theproximal end portion 614 shown in FIG. 11A. Moreover, it is appreciatedthat the expandable members of FIGS. 1A, 4A, 6A, 7A, 7C, 10, 14, 15 and19-24 may be modified in a way so as to eliminate the distal end portion(e.g., distal end portion 18 in FIG. 1A) so that there exists only aproximal end portion and main body portion like that of FIG. 11A.

FIG. 12 illustrates a vascular treatment device 700 in accordance withanother embodiment of the present invention. FIG. 12 depicts device 700in a two-dimensional plane view as if the device were cut and laid flaton a surface. In the embodiment of FIG. 12, expandable member 712includes a plurality of generally longitudinal undulating elements 724with adjacent undulating elements being interconnected by a plurality ofcurved connectors 728 to form a plurality of closed-cell structures 726disposed about the length of the expandable member 712. In theembodiment shown, the expandable member 712 includes a cylindricalportion 716 and a distal end portion 718 with the cell structures 726 inthe cylindrical portion 716 extending continuously and circumferentiallyaround a longitudinal axis 730 of the expandable member 712. The cellstructures 726 in the distal end portion 718 extend less thancircumferentially around the longitudinal axis 730 of the expandablemember 712. In a manner similar to that described in conjunction withthe embodiment of FIG. 10, attached to or otherwise coupled to each ofthe proximal-most cell structures 728 are proximally extending elongateflexible wires 740. This arrangement enables the pushing force appliedto the proximal end of the expandable member 712 to be more evenlydistributed about its proximal circumference. In another embodiment,although not shown in FIG. 12, the proximal-most strut elements 730 havea width and/or thickness greater than the struts in the other portionsof the expandable member 712. Such a feature further contributes to thepush force being evenly distributed about the circumference of theexpandable member 712 and also inhibits the strut elements directlyreceiving the push force from buckling.

As previously discussed, in use, the expandable members of the presentinvention are advanced through the tortuous vascular anatomy of apatient to a treatment site, such as an embolic obstruction, in anunexpanded or compressed state of a first nominal diameter and aremovable from the unexpanded state to a radially expanded state of asecond nominal diameter greater than the first nominal diameter fordeployment at the treatment site. One manner of delivering and deployingexpandable member 912 at the site of an embolic obstruction 950 is shownin FIGS. 13A through 13C. As shown in FIG. 13A, a delivery catheter 960having an inner lumen 962 is advanced to the site of the embolicobstruction 950 so that its distal end 964 is positioned distal to theobstruction. After the delivery catheter 960 is in position at theembolic obstruction 950, the retrieval device 900 is placed into thedelivery catheter by introducing the expandable member 912 into aproximal end of the delivery catheter (not shown) and then advancing theexpandable member 912 through the lumen 962 of the delivery catheter byapplying a pushing force to elongate flexible wire 940. By the use ofradiopaque markings and/or coatings positioned on the delivery catheter960 and device 900, the expandable member 912 is positioned at thedistal end of the delivery catheter 960 as shown in FIG. 13B so that themain body portion 916 is longitudinally aligned with the obstruction950. Deployment of the expandable member 912 is achieved by proximallywithdrawing the delivery catheter 960 while holding the expandablemember 912 in a fixed position as shown in FIG. 13C. Once the expandablemember 912 has been deployed to an expanded position within theobstruction 950, the expandable member 912 is retracted, along with thedelivery catheter 960, to a position outside the patient. In oneembodiment, the expandable member 912 is first partially retracted toengage with the distal end 964 of the delivery catheter 960 prior tofully retracting the devices from the patient.

In one embodiment, once the expandable member 912 is expanded at theobstruction 950, it is left to dwell there for a period of time in orderto create a perfusion channel through the obstruction that causes theobstruction to be lysed by the resultant blood flow passing through theobstruction. In such an embodiment, it is not necessary that theexpandable member 912 capture a portion of the obstruction 950 forretrieval outside the patient. When a sufficient portion of theobstruction 950 has been lysed to create a desired flow channel throughthe obstruction, or outright removal of the obstruction is achieved bythe resultant blood flow, the expandable member 912 may be withdrawninto the delivery catheter 960 and subsequently removed from thepatient.

In another embodiment, the expandable member 912 is expanded at theobstruction 950 and left to dwell there for a period of time in order tocreate a perfusion channel through the obstruction that causes theobstruction to be acted on by the resultant flow in a manner that makesthe embolic obstruction more easily capturable by the expandable memberand/or to make it more easily removable from the vessel wall of thepatient. For example, the blood flow created through the embolicobstruction may be made to flow through the obstruction for a period oftime sufficient to change the morphology of the obstruction that makesit more easily captured by the expandable member and/or makes it moreeasily detachable from the vessel wall. As in the preceding method, thecreation of blood flow across the obstruction 950 also acts to preservetissue. In one embodiment, the blood flow through the obstruction may beused to lyse the obstruction. However, in this modified method, lysingof the obstruction is performed for the purpose of preparing theobstruction to be more easily captured by the expandable member 912.When the obstruction 950 has been properly prepared, for example bycreating an obstruction 950 of a desired nominal inner diameter, theexpandable member 912 is deployed from the distal end 964 of thedelivery catheter 940 to cause it to engage with the obstruction.Removal of all, or a portion, of the obstruction 950 from the patient isthen carried out in a manner similar to that described above.

In yet another embodiment, once the expandable member 912 has beendelivered and expanded inside the obstruction 950, it may be detachedfrom the elongate wire 940 for permanent placement within the patient.In such an embodiment, the manner in which the elongate wire 940 isattached to the expandable member 912 allows the two components to bedetached from one another. This may be achieved, for example, by the useof a mechanical interlock or an erodable electrolytic junction betweenthe expandable member 912 and the elongate wire 940.

As described herein, the expandable members of the various embodimentsmay or may not include distal wire segments that are attached to theirdistal ends. In alternative preferred embodiments, vascular treatmentdevices that are configured to permanently place an expandable member atthe site of an embolic obstruction do not include distal wire segmentsattached to the distal ends of the expandable members.

One advantage associated with the expandable member cell patterns of thepresent invention is that withdrawing the expandable members by theapplication of a pulling force on the proximal elongate wire flexiblewire urges the expandable members to assume a smaller expanded diameterwhile being withdrawn from the patient, thus decreasing the likelihoodof injury to the vessel wall. Also, during clot retrieval as the profileof the expandable members decrease, the cell structures collapse andpinch down on the clot to increase clot retrieval efficacy. Anotheradvantage is that the cell patterns permit the expandable members to beretracted into the lumen of the delivery catheter after they have beenpartially or fully deployed. As such, if at any given time it isdetermined that the expandable member has been partially or fullydeployed at an improper location, it may be retracted into the distalend of the delivery catheter and repositioned to the correct location.

With reference to FIG. 14, a modified version of the vascular treatmentdevice 200 of FIG. 6A is shown that includes thin strut elements 280intersecting at least some of the cell structures 226 located in thecylindrical main body portion 216 of expandable member 212. The thinstrut elements 280 are dimensioned to have a width of less than thestrut elements 282 that form the cell structures 226. In alternativeexemplary embodiments, strut elements 280 have an as-cut or polishedwidth dimension that is between about 25% to about 50% smaller than therespective as-cut or polished width dimension of struts 262. When usedfor the purpose of clot retrieval, a purpose of the thin struts 280 isto enhance the expandable member's ability to engage with and capture anembolic obstruction. This is accomplished by virtue of several factors.First, the thinner width dimensions of the struts 280 make it easier forthe struts to penetrate the obstruction. Second, they act to pinchportions of the entrapped obstruction against the outer and wider strutelements 282 as the expandable member is deployed within theobstruction. Third, they may be used to locally enhance radial forcesacting on the obstruction. It is important to note that the use of thinstrut elements 280 is not limited to use within cell structures 226 thatreside within the cylindrical main body portion 216 of the expandablemember 212. They may be strategically positioned in any or all of thecell structures of the expandable member. Moreover, it is important tonote that the use of thin strut elements 280 is not limited to theembodiment of FIG. 6, but are applicable to all the various embodimentsdisclosed herein. Lastly, in alternative exemplary embodiments, as shownin FIG. 15, multiple thin strut elements 280 are provided within one ormore of the cell structures 226, and may also be used in conjunctionwith cell structures that have a single thin strut element and/or cellstructures altogether devoid of thin strut elements.

In the treatment of aneurysms when the treatment device is used for thepurpose of diverting flow, the density of the cell structures 226 issufficient to effectively divert flow away from the aneurysm sack. Inalternative embodiments in lieu of, or in combination with adjusting thedensity of the cell structures 226, intermediate strut elements similarto the strut elements 280 of FIGS. 14 and 15 are used to increase theeffective wall surface of the expandable member. In these embodiments,the intermediate strut elements may have the same, smaller, larger, orany combination thereof, dimensional characteristics of the cellstructure struts. Conversely, in alternative embodiments for use in thetreatment of aneurysms for the purpose placing coils or other likestructures within the sack of the aneurysm, the size of the cellstructures 226 is sufficient to facilitate passage of the coils throughthe cell structures.

FIG. 16 illustrates a treatment device according to the embodiment ofFIGS. 6A and 6B, wherein the pushability of the expandable member 212during its advancement to the treatment site of a patient is enhanced bythe inclusion of an internal wire segment 241 that extends between theproximal end 220 and distal end 222 of the expandable member 212. Inthis manner, the pushing force applied by elongate wire 240 istransmitted to both the proximal and distal ends of expandable device.The internal wire segment may be a discrete element that is attached tothe proximal and distal ends of the expandable member, or may preferablybe a co-extension of the elongate flexible wire 240. During delivery ofthe expandable member 212 to the treatment site in its compressed state,the internal wire segment 241 assumes a substantially straight or linearconfiguration so as to adequately distribute at least a part of thepushing force to the distal end 222 of the expandable member. When theexpandable member 212 expands, it tends to foreshorten causing slack inthe internal wire segment 241 that forms a long-pitched helix within theexpandable member as shown in FIG. 16. An additional advantageassociated with the use the internal wire segment 241 is that theformation of the internal helix upon expansion of the expandable member212 assists in capturing the embolic obstruction.

In an alternative embodiment, as shown in FIG. 17, the pushability ofthe expandable member 212 during its advancement to the treatment siteof a patient is enhanced by the inclusion of an external wire segment243 that extend between the proximal end 220 and distal end 222 of theexpandable member 212. In this manner, the pushing force applied by theelongate wire 240 is transmitted to both the proximal and distal ends ofthe expandable device. The external wire segment may be discrete elementthat is attached to the proximal and distal ends of the expandablemember, or may preferably be a co-extension of the elongate flexiblewire 240. During delivery of the expandable member 212 to the treatmentsite in its compressed state, the external wire segment 243 assumes asubstantially straight or linear configuration so as to adequatelydistribute at least a part of the pushing force to the distal end 222 ofthe expandable member. When the expandable member 212 expands, it tendsto foreshorten causing slack in the external wire segment 243 as shownin FIG. 17. An additional advantage associated with the use of theexternal wire segment 243 is that it directly acts on the obstructionwhile the expandable member 212 is expanded to assist in engaging andcapturing the embolic obstruction.

In yet another embodiment, a distal emboli capture device 251 isdisposed on the distal wire segment 250, or otherwise attached to thedistal end 222, of expandable member 212 as shown in FIG. 18. Thefunction of the distal emboli capture device 251 is to capture embolithat may be dislodged from the embolic obstruction during the expansionof the expandable member 212 or during its removal from the patient toprevent distal embolization. In FIG. 18, the distal emboli capturedevice is shown as a coil. In alternative embodiments, baskets, embolicfilters or other known emboli capture devices may be attached to thedistal end 222 or distal wire segment 250 of expandable member 12.

Again, as with the embodiments of FIGS. 14 and 15, it is important tonote that the features described in conjunction with FIGS. 16, 17 and 18are not limited to the embodiment of FIG. 6, but are applicable to allthe various embodiments disclosed herein.

FIG. 19 illustrates a bodily duct or vascular treatment device 1000 inaccordance with another embodiment of the present invention. FIG. 19depicts device 1000 in a two-dimensional plane view as if the devicewere cut and laid flat on a surface. Device 1000 includes an expandablemember 1012 having a proximal end portion 1024, a cylindrical main bodyportion 1026 and a distal end portion 1028 with an elongate flexiblewire 1014 attached to or otherwise coupled to the proximal end 1020 ofthe expandable member. The construction of device 1000 is similar todevice 200 described above in conjunction with FIG. 6A except that thecell structures 1018 and 1019 in the proximal end portion 1024 are moreclosely symmetrically arranged than the cell structures in the proximalend portion 214 of device 200. The more substantial symmetricalarrangement of the cell structures in the proximal end portion 1024 ofdevice 1000 facilitates the loading or retrieval of the expandablemember 1012 into a lumen of a delivery catheter or sheath (not shown) bycausing the proximal end portion 1024 to collapse more evenly duringcompression. The proximal wall segments 1016 of cell structures 1018 and1019 comprise linear or substantially linear strut elements as viewed inthe two dimension plane view of FIG. 19. In one embodiment, the linearstrut elements 1016 are aligned to form continuous and substantiallylinear rail segments 1017 that extend from the proximal end 1020 ofproximal end portion 1024 to a proximal-most end of main body portion1026 (again, as viewed in the two dimension plane view of FIG. 19) andpreferably are of the same length. In alternative embodiments, the angleθ between the wire segment 1014 and rail segments 1017 ranges betweenabout 140 degrees to about 150 degrees. In one embodiment, one or bothof the linear rail segments 1017 have a width dimension W1 which isgreater than the width dimension of the adjacent strut segments of cellstructures 1018 and/or 1019 and/or 1030. An enhanced width dimension W1of one or both the linear rail segments 1017 further enhances the railsegments' ability to distribute forces and resist buckling when a pushforce is applied to them. In another implementation, one or both of thelinear rail segments 1017 are provided with an enhanced thicknessdimension, rather than an enhanced width dimension to achieve the sameor similar result. In yet an alternative implementation, both the widthand thickness dimensions of one or both of the linear rail segments 1017are enhanced to achieve the same or similar results. In yet anotherimplementation, the width and/or thickness dimensions of each of therail segments 1017 differ in a manner that causes a more evencompression of the proximal end portion 1024 of the expandable member1012 when it is collapsed as it is loaded or retrieved into a deliverycatheter or sheath.

Although the description that follows is directed to the embodiment ofFIG. 19, it is important to note that the provision of a slit ascontemplated by the embodiments of FIGS. 20-22 are applicable to all thevascular treatment devices described herein, and their numerousembodiments and modifications thereof.

Turning now to FIG. 20, the treatment device 1000 of FIG. 19 is depictedhaving a longitudinal slit 1040 that extends from the proximal end 1020to the distal end 1022 of the expandable member 1012. The slit 1040permits the cell structures 1018, 1019 and 1030 to move relative to oneanother in a manner that inhibits the individual strut elements 1032 ofthe expandable member 1012 from buckling during compression of theexpandable member 1012 as it is loaded or retrieved into a deliverycatheter or sheath. In alternative embodiments, slit 1040 extends lessthan the entire length of expandable member 1012 and is arranged toinhibit buckling of strategically important strut elements that mostaffect the expandable member's ability to be effectively loaded orwithdrawn into a delivery catheter or sheath. For example, in oneembodiment, slit 1040 is provided only in the proximal end portion 1024of the expandable member 1012 where the likelihood of buckling orbending of struts 1032 is most likely to occur. In another embodiment,slit 1040 is provided in both the proximal end portion 1024 and thecylindrical main body portion 1026 of expandable member 1012.

FIG. 21 illustrates the treatment device 1000 of FIG. 19 having adiagonally disposed/spiral slit 1050 that extends the entirecircumference of the expandable member 1012. In one embodiment, asillustrated in FIG. 21, the spiral slit 1050 originates at the distalposition, or at a point adjacent to the distal position, of the proximalend portion 1024 of expandable member 1012. With respect to theembodiments having linear rail segments, such as the linear railsegments 1017 of FIG. 19, the spiral slit 1050 originates at the distalposition 1021 of one of the linear rail segments 1017, or at a pointdistally adjacent to the distal position 1021, as shown in FIG. 21.Testing of the various vascular treatment devices described herein hasshown that the occurrence of buckling tends to occur at the strutelements located adjacent to the distal positions of the proximal endportions of the expandable members. This phenomenon is exacerbated inthe expandable members having proximal end portions with linear railsegments. For this reason, and with reference to FIG. 21, theoriginating point of spiral slit 1050 is located at or adjacent to adistal position 1021 of one of the linear rail segments 1017. Anadvantage of the diagonally disposed and/or spiral slit configuration ofFIG. 21 is that it originates where the buckling tends to originate andfurther inhibits buckling of strut elements 1032 along the length of theexpandable member 1012. As shown in FIG. 22, in alternative embodimentsslit 1050 extends diagonally along only a portion of the circumferenceof the cylindrical main body portion 1026 of the expandable member 1012.In the embodiment of FIG. 22, slit 1050 originates at the distalposition 1021 of linear rail segment 1017. In alternative embodiments,where buckling of individual strut elements 1032 originate at a pointother than at the distal point of the proximal end portion 1024 of theexpandable member 1012, the originating point of the slit 1050 islocated at the origination point of the bucking (absent the slit 1050)and extends in a longitudinal direction distally therefrom.

FIG. 23 illustrates a bodily duct or vascular treatment device 2000 inaccordance with an embodiment of the present invention. FIG. 23 depictsdevice 2000 in a two-dimensional plane view as if the device were cutand laid flat on a surface. Device 2000 includes a self-expandablemember 2012 that is attached or otherwise coupled to an elongateflexible wire 2040 that extends proximally from the expandable member2012. In one embodiment, the expandable member 2012 is made of shapememory material, such as Nitinol, and is preferably laser cut from atube. In one embodiment, the expandable member 2012 has an integrallyformed proximally extending wire segment 2042 that is used to join theelongate flexible wire 2040 to the expandable member 2012. In such anembodiment, flexible wire 2040 may be joined to wire segment 2042 by theuse of solder, a weld, an adhesive, or other known attachment method. Inan alternative embodiment, the distal end of flexible wire 2040 isattached directly to a proximal end 2020 of the expandable member 2012.

In the embodiment of FIG. 23, expandable member 2012 includes aplurality of generally longitudinal undulating elements 2024 withadjacent undulating elements being coupled to one another in a manner toform a plurality of circumferentially-aligned cell structures 2026. Theexpandable member 2012 includes a proximal end portion 2013, acylindrical main body portion 2014 and a distal end portion 2015 withthe cell structures 2026 in the main body portion 2014 extendingcontinuously and circumferentially around a longitudinal axis 2032 ofthe expandable member 2012. The cell structures in the proximal endportion 2013 and distal end portion 2015 extend less thancircumferentially around the longitudinal axis 2032 of the expandablemember 2012. The proximal wall segments 2016 of cell structures 2027,2028, 2029 and 2030 comprise linear or substantially linear strutelements as viewed in the two dimension plane view of FIG. 23. In oneembodiment, the linear strut elements 2016 are aligned to formcontinuous and substantially linear rail segments 2017 that extend fromthe proximal end 2020 of proximal end portion 2013 to a proximal-mostend of main body portion 2014 (again, as viewed in the two dimensionplane view of FIG. 23) and preferably are of the same length. Asdescribed above in conjunction with FIGS. 6A and 6B, rail segments 2017are not in fact linear but are of a curved and non-undulating shape.This configuration advantageously provides rail segments 2017 devoid ofundulations thereby enhancing the rail segments' ability to distributeforces and resist buckling when a push force is applied to them. Inalternative preferred embodiments, the angle θ between the wire segment2042 or 2040, which ever the case may be, and rail segments 2017 rangesbetween about 140 degrees to about 150 degrees. In one embodiment thelinear rail segments 2017 have a width dimension which is greater thanthe width dimension of the adjacent strut segments of cell structures2027 and/or 2028 and/or 2029 and/or 2030 and/or 2026. An enhanced widthof the linear rail segments 2017 further enhances the rail segments'ability to distribute forces and resist buckling when a push force isapplied to the expandable member. In another implementation the linearrail segments 2017 are provided with an enhanced thickness dimension,rather than an enhanced width dimension to achieve the same or similarresult. In yet an alternative implementation, both the width andthickness dimensions of the linear rail segments 2017 are enhanced toachieve the same or similar results.

In one embodiment, the width and/or thickness of the internal strutelements 2080 of proximal-most cell structure 2027 is also enhanced soas to resist buckling of these elements while the expandable member isbeing pushed through a sheath or delivery catheter. In one exemplaryembodiment, the “as-cut” nominal widths of the enhanced strut elements2016 and 2080 are about 0.0045 inches, while the “as-cut” nominal widthof the other strut elements are about 0.003 inches.

FIGS. 24A and 24B illustrate a vascular treatment device 3000 of anotherembodiment of the present invention. FIG. 24A depicts device 3000 in atwo-dimensional plane view as if the device were cut and laid flat on asurface. FIG. 24B depicts the device in its manufactured and/or expandedtubular configuration. The overall design of device 3000 is similar tothe design of device 2000 depicted and described above in reference toFIG. 23. The primary difference between the two designs lays in thelength “L” to width “W” ratio of the cell structures 2026, 2027, 2028,2029 and 2030. The length to width ratios of the cells structures ofFIG. 24A are generally greater than the length to width ratios of therespective cell structures of FIG. 23. As illustrated, the lengths “L”of the cell structures of the device of FIG. 24A, in the “as-cut”configuration are generally greater than the lengths of the respectivecell structures of FIG. 23, while the widths “W” of the cell structuresof the device of FIG. 24A are generally smaller than the width of therespective cell structures of FIG. 23. As a result, the slope of theindividual strut elements 2040 in the cell structures of FIG. 24A aregenerally smaller than the slopes of the respective strut elements inthe cell structures of FIG. 23. By reducing the slope of the strutelements 2040 and leaving the other dimensional and materialcharacteristics constant, the effective radial force along the length ofthe struts 2040 is reduced. The effect of such a reduction is that thesummation of axial force components along lines A-A of the device ofFIG. 24 more closely matches the summation of the radial forcecomponents along lines B-B as compared to the device of FIG. 23. Throughexperimentation, the inventors have discovered that an “as-cut” cellstructure length to width ratio of greater than about 2.0, and an“expanded” cell structure length to width ratio of a greater than about1.25, advantageously resulted in a longitudinal radial forcedistribution along the length of the expandable member 2012 thatenhanced the expandable member's ability to be pushed through andwithdrawn into a lumen of a delivery catheter.

FIGS. 26, 27A and 27B illustrate an expandable member 5000 in anotherimplementation. Expandable member 5000 includes a plurality of generallylongitudinal undulating elements 5024 with adjacent undulating elementsbeing out-of-phase with one another and connected in a manner to form aplurality of diagonally disposed cell structures 5026 angularly disposedbetween about 40.0 to about 50.0 degrees with respect to one another. Inone implementation, the cell structures are diagonally displaced alongabout a 45.0 degree line. The expandable member 5000 includes a proximalend portion 5014, a cylindrical main body portion 5016 and a distal endportion 5018 with the cell structures 5026 in the main body portion 5016extending continuously and circumferentially around a longitudinal axisof the expandable member 5000. The cell structures 5026 in the proximalend portion 5014 and distal end portion 5018 extend less thancircumferentially around the longitudinal axis of the expandable member5000. In one implementation, the expandable member has an unexpanded orcrimped nominal diameter of about 1.0 millimeters and a designed maximumimplantable diameter of about 4.0 millimeters.

In one embodiment, expandable member 5000 has an overall lengthdimension A of about 36.0±2.0 millimeters with the main body portion5016 having a length P of about 19.0±2.0 millimeters. In oneimplementation the strut width dimension N and thickness dimension Owithin the main body portion 5016 are about 0.0021±0.0004 inches andabout 0.0032±0.0005 inches, respectively, while the strut widthdimension L of the proximal rails 5030 is about 0.0039±0.004 inches.

In use, expandable member 5000 is advanced through the tortuous vascularanatomy or bodily duct of a patient to a treatment site in an unexpandedor compressed state (not shown) of a first nominal diameter and ismovable from the unexpanded state to a radially expanded state of asecond nominal diameter greater than the first nominal diameter fordeployment at the treatment site. In alternative exemplary embodimentsthe first nominal diameter (e.g., average diameter of main body portion5016) ranges between about 0.017 to about 0.030 inches, whereas thesecond nominal diameter (e.g., average diameter of main body portion5016) is between about 2.5 to about 5.0 millimeters. In oneimplementation, the dimensional and material characteristics of the cellstructures 5026 residing in the main body portion 5016 of the expandablematerial 5000 are selected to produce sufficient radial force andcontact interaction to cause the cell structures 5026 to engage with anembolic obstruction residing in the vascular in a manner that permitspartial or full removal of the embolic obstruction from the patient. Inother embodiments the dimensional and material characteristics of thecell structures 5026 in the main body portion 5016 are selected toproduce a radial force per unit length of between about 0.005 N/mm toabout 0.050 N/mm, preferable between about 0.010 N/mm to about 0.050N/mm, and more preferably between about 0.030 N/mm and about 0.050 N/mm.In one embodiment, the diameter of the main body portion 5016 in adesigned fully expanded implanted state is about 4.0 millimeters withthe cell pattern, strut dimensions and material being selected toproduce a radial force of between about 0.030 N/mm to about 0.050 N/mmwhen the diameter of the main body portion is reduced to 1.5millimeters. In the same or alternative embodiment, the cell pattern,strut dimensions and material(s) are selected to produce a radial forceof between about 0.010 N/mm to about 0.020 N/mm when the diameter of themain body portion is reduced to 3.0 millimeters.

FIG. 29 shows an overall radial force exerted along the length of theexpandable member 5000 as a function of the diameter of the expandablemember 5000 according some implementations.

FIG. 30 illustrates clot retrieval devices 6000 according to otherimplementations where, among other features, the strut elements of railsegments 6001 and 6002 have varying width dimensions. FIG. 30 depicts aclot retrieval device in a two-dimensional plane view as if the devicewere cut and laid flat on a surface. FIG. 30 depicts the device in itsmanufactured (as-cut) configuration. In one implementation, rail segment6001 transitions from a maximum width dimension at or near its proximalend 6014 to a minimum width dimension at or near its distal end 6015. Ina like manner, rail segment 6002 transitions from a maximum widthdimension at or near its proximal end 6014 to a minimum width dimensionat or near its distal end 6016. As previously discussed, the widthdimensions of the rail segments are selected to enhance their ability todistribute forces and to resist buckling when a push force is applied tothe proximal end 6014 of the vascular treatment device. In someimplementations the percentage change between the maximum rail widthdimension and the minimum rail width dimension is between about 20.0%and about 50.0%. In other implementations the percentage change betweenthe maximum rail width dimension and the minimum rail width dimension isbetween about 25.0% and about 45.0%. In other implementations thepercentage change between the maximum rail width dimension and theminimum rail width dimension is between about 35.0% and about 45.0%. Inan exemplary implementation the width dimension of the rail segmentstransitions from a maximum width dimension of about 0.0047±0.0004 inchesto a minimum width dimension of about 0.0027±0.0004 inches. In anotherexemplary implementation the width dimension of the rail segmentstransitions from a maximum width dimension of about 0.0047±0.0004 inchesto a minimum width dimension of about 0.0035±0.0004 inches. In anotherexemplary implementation the width dimension of the rail segmentstransitions from a maximum width dimension of about 0.0047±0.0004 inchesto a minimum width dimension of about 0.0037±0.0004 inches. As discussedabove, post-polishing of the devices generally involve an etchingprocess that typically results in a 40% to 50% reduction in the as-cutcross-sectional dimensions.

Although FIG. 30 represents rail segments devoid of undulations, aspreviously described herein, it is appreciated that rail segments suchas those shown in FIGS. 1A and 4A are also contemplated. Moreover, it isappreciated that other than the rail width characteristics disclosedabove, any number of the features and/or characteristics of the vasculartreatment devices previously disclosed herein with respect to FIGS. 1through 29 (e.g., dimensional, spatial, relational, etc.) may beincorporated into a clot retrieval device 6000 according to FIG. 30.

In some implementations the width of rails 6001 and 6002 taper alongtheir length (or a portion thereof) in a substantial uniform anddiminishing fashion. In some implementations discrete portions of therails have a substantially uniform width dimension with transitionaltapers being used to join rail portions of different widths. In someimplementations discrete portions of the rails have a substantiallyuniform width dimension with stepped transitions between rail portionsof different widths. In other implementations two or more of thepreceding width transitional methods are utilized. Although notrequired, it is preferable that the width transitions occur at portionsalong the rail struts other than at a junction of the struts (e.g.,junctions 6030).

In some implementations, as previously described, struts 6012 and 6013of the most proximal cell structure 6018 also have an enhanced widthdimension that may be equal to or less than the maximum rail widthdimension for the purpose of enhancing the pushability of the clotretrieval device as it is advanced through the tortuous anatomy of apatient. In some implementations less than the entire length of struts6012 and 6013 are provided with an enhanced width dimension. Forexample, in some implementations an enhanced width portion extends froma proximal most end of struts 6012 and 6013 and terminates a distanceprior to juncture 6026. The configuration of struts 6012 and 6013 mayalso be altered in manners previously disclosed.

With continued reference to FIG. 30, in exemplary implementations all orportions of struts 6003 and 6004 (and optionally all or the proximalportions of struts 6005 and 6006) have width dimensions between about0.0045 inches and about 0.0050 inches, all or portions of struts 6007and 6008 (and optionally all or the distal portions of struts 6005 and6006) have width dimensions between about 0.0035 inches and about 0.0036inches, all or portions of struts 6009 and 6010 (and optionally all orthe distal portions of struts 6007 and 6008) have width dimensionsbetween about 0.0027 inches and about 0.0035 inches, and with asubstantial portion of the strut elements in the remaining portions ofthe device (portions A, B and C) having width dimensions between about0.0027 inches and about 0.0034 inches. In one or more of the immediatelypreceding implementations, the width dimension of struts 6012 and 6013is between about 0.0033 inches and about 0.0047 inches, and preferablybetween about 0.0033 inches and about 0.0040 inches. It is to beappreciated that the dimensions disclosed throughout this disclosurerelate to exemplary implementations and are also subject to customarymanufacturing tolerances. Variations in the dimensions are possible andcontemplated.

Although not required, it is preferable that the width transitions occurat portions along the struts themselves other than at a junction of thestruts (e.g., junctions 6030 and 6032).

In one exemplary implementation struts 6003-6006 have a width dimensionof about 0.0047 inches, struts 6007, 6008 and a proximal portion ofstrut 6010 have a width dimension of about 0.0036 inches, struts 6009,6011 and a distal portion of strut 6010 have a width dimension of about0.0035 inches, struts 6012-6013 have a width dimension of about 0.0036inches, with all or a substantial portion of the remaining strutelements of the treatment device having a width dimension of about0.0027 inches.

Testing has shown the proximal taper region of the treatment devices ofFIG. 30 to possess good force transmission characteristics along withgood radial force characteristics that provide good sheathing andre-sheathing of the proximal taper portion into an introducer sheathand/or delivery catheter.

In another exemplary implementation struts 6003-6006 have a widthdimension of about 0.0047 inches, struts 6007, 6008 and a proximalportion of strut 6010 have a width dimension of about 0.0036 inches,struts 6009, 6011 and a distal portion of strut 6010 have a widthdimension of about 0.0035 inches, struts 6012-6013 have a widthdimension of about 0.0036 inches, the remaining strut elements insection A of the clot retrieval device having a width dimension of about0.0033 inches and the remaining strut elements generally located insections B and C of the clot retrieval device having a width dimensionof about 0.0027 inches. The increased width dimension of the struts insection A advantageously reduces the likelihood of struts bucklingwithin the proximal taper region of the clot retrieval device and alsoincreases the radial strength of the proximal taper region.

In another exemplary implementation struts 6003-6006 have a widthdimension of about 0.0047 inches, struts 6007, 6008 and a proximalportion of strut 6010 have a width dimension of about 0.0036 inches,struts 6009, 6011 and a distal portion of strut 6010 have a widthdimension of about 0.0035 inches, the remaining strut elements insection D of the treatment device having a width dimension of about0.0033 inches and the remaining strut elements of sections B and C ofthe treatment device having a width dimension of about 0.0027 inches.The increased width dimension of the struts in section A advantageouslyreduces the likelihood of struts buckling within the proximal taperregion of the clot retrieval device during its delivery to a treatmentsite of a patient and also increases the radial strength of the proximaltaper region.

In another exemplary implementation struts 6003-6006 have a widthdimension of about 0.0047 inches, struts 6007, 6008 and a proximalportion of strut 6010 have a width dimension of about 0.0036 inches,struts 6009, 6011 and a distal portion of strut 6010 have a widthdimension of about 0.0035 inches, struts 6012-6013 have a widthdimension of about 0.0036 inches, the strut elements generally locatedin section C of the clot retrieval device having a width dimension ofabout 0.0033 inches, and the remaining strut elements of sections A andB of the clot retrieval device having a width dimension of about 0.0027inches. The increased width dimension of the struts in section Cadvantageously reduces the likelihood of struts buckling within thedistal taper region of the clot retrieval device during its delivery toa treatment site of a patient. The increased width dimension alsoincreases the radial strength of the proximal taper region that enhancesthe ability of the distal taper region to remain open while the clotretrieval device is withdrawn from a patient. This feature isparticularly advantageous when the clot retrieval device is used forclot removal in that it enables the distal taper section to remain openand sweep away remaining portions of the clot when the clot retrievaldevice is being withdrawn from the patient.

According to some implementations the clot retrieval devices 6000according to FIG. 30 are laser cut from a tube having an inner diameterof about 2.667 millimeters and a wall thickness of between about 0.102millimeters to about 0.126 millimeters. In use, a clot retrieval device6000 according to an implementation of that shown in FIG. 30 is advancedthrough the tortuous vascular anatomy or bodily duct of a patient to atreatment site in an unexpanded or compressed state of a first nominaldiameter and is movable from the unexpanded state to a radially expandedstate of a second nominal diameter greater than the first nominaldiameter for deployment at the treatment site. In alternative exemplaryembodiments the second nominal diameter (e.g., average diameter of mainbody portion) is about 4.0±0.5 millimeters. In some implementation, thedimensional and material characteristics of the cell structures 6020generally residing in the main body (section B) of the expandablematerial are selected to produce sufficient radial force and contactinteraction to cause the cell structures 6020 to engage with an embolicobstruction/clot residing in the vascular in a manner that permitspartial or full removal of the embolic obstruction from the patient.

In some implementations the dimensional and material characteristics ofthe elements along the expandable length of the retrieval device areselected to produce a radial force per unit length of between about0.030 N/mm to about 0.055 N/mm when the outer diameter of the retrievaldevice is restrained to 1.5 millimeters. In some implementations thedimensional and material characteristics of the elements along theexpandable length are selected to produce a radial force per unit lengthof between about 0.035 N/mm to about 0.050 N/mm when the outer diameterof the retrieval device is restrained to 1.5 millimeters. In someimplementations the dimensional and material characteristics of theelements along the expandable length are selected to produce a radialforce per unit length of between about 0.037 N/mm to about 0.049 N/mmwhen the outer diameter of the retrieval device is restrained to 1.5millimeters. Among the same or alternative implementations, thedimensional and material characteristics of the elements along theexpandable length of the retrieval device are selected to produce aradial force of between about 0.010 N/mm to about 0.020 N/mm when thenominal diameter of the main body portion is about 3.0±0.5 millimeters.

In the implementations of FIG. 30, many of the cell structures(excluding those that are formed at least in part by rail segments 6001and 6002) are shown having similar shapes with most of the cellstructure including a pair of short struts 6022 and a pair of longstruts 6023. According to some implementations the area of the cells areabout 4.00±0.5 mm². In an exemplary implementation the cell areas areabout 4.2 mm². In exemplary implementations, short struts 6022 have alength of between about 0.080 and about 0.100 inches, long struts 6023have a length of between about 0.130 and about 0.140 inches to produce astaggered cell arrangement about the circumference of the treatmentdevice. In some implementations the overall length of the expandableportion of the clot retrieval device is between about 35.0 to about 45.0millimeters with the main body portion (section B) having a length ofabout 20.0 to about 25.0 millimeters. In one exemplary embodiment theoverall length of the expandable portion of the clot retrieval device isabout 42.7 millimeters with the main body portion (section B) having alength of about 21.7 millimeters and the proximal and distal taperregions having a length of about 12.4 millimeters and about 8.6millimeters, respectively.

FIG. 31 illustrates clot retrieval devices 6050 according to otherimplementations where, among other features, the strut elements of railsegments 6051 and 6052 have varying width dimensions. Clot retrievaldevice 6050 is particularly adapted for the treatment of small diametervessels/duct. In one implementation, as shown in FIG. 31, thecircumference of the main body portion (section A) comprises three cellstructures 6080, but is not limited to such a construction. FIG. 31depicts the clot retrieval treatment device 6050 in a two-dimensionalplane view as if the device were cut and laid flat on a surface. FIG. 31depicts the device in its manufactured (as-cut) configuration. In oneimplementation, rail segment 6051 transitions from a maximum widthdimension at or near its proximal end 6053 to a minimum width dimensionat or near its distal end 6054. In a like manner, rail segment 6052transitions from a maximum width dimension at or near its proximal end6053 to a minimum width dimension at or near its distal end 6055. Aspreviously discussed, the width dimensions of the rail segments areselected to enhance their ability to distribute forces and to resistbuckling when a push force is applied to the proximal end 6053 of thevascular treatment device. In some implementations the percentage changebetween the maximum rail width dimension and the minimum rail widthdimension is between about 20.0% and about 30.0%, and preferably betweenabout 20% and about 25%. In an exemplary implementation the widthdimension of the rail segments transitions from a maximum widthdimension of about 0.0047±0.0004 inches to a minimum width dimension ofabout 0.0036±0.0004 inches.

Although FIG. 31 represents rail segments 6051 and 6052 that are devoidof undulations, as previously described herein, it is appreciated thatrail segments such as those shown in FIGS. 1A and 4A are alsocontemplated. Moreover, it is appreciated that other than the rail widthcharacteristics disclosed above, any number of the features and/orcharacteristics of the treatment devices previously described hereinwith respect to FIGS. 1 through 29 (e.g., dimensional, spatial,relational, etc.) may be incorporated into a clot retrieval device 6050according to FIG. 31.

In some implementations the width of rail 6051 and 6052 taper alongtheir length (or a portion thereof) in a substantial uniform anddiminishing fashion. In some implementations discrete portions of therails have a substantially uniform width dimension with onlytransitional tapers being used to join rail portions of differentwidths. In some implementations discrete portions of the rails have asubstantially uniform width dimension with stepped transitions betweenrail portions of different widths. In other implementations two or moreof the preceding width transitional methods are utilized. Although notrequired, it is preferable that the width transitions occur at portionsalong the rail struts other than strut junctions (e.g., junctions 6064).

In some implementations struts 6056 and 6057 of the most proximal cellstructure also have enhanced width dimensions that may be equal to orless than the maximum rail width dimension for the purpose of enhancingthe pushability of the clot retrieval device as it is advanced throughthe tortuous anatomy of a patient. In some implementations less than theentire length of struts 6056 and 6057 are provided with an enhancedwidth dimension. For example, in some implementations an enhanced widthportion extends from a proximal most end of struts 6056 and 6057 andterminates a distance prior to juncture 6058. Moreover, theconfiguration of struts 6056 and 6057 may also be altered in mannerspreviously disclosed.

With continued reference to FIG. 31, in exemplary implementations railportions 6060 and 6061 have width dimensions of about 0.0047 and railportions 6062 and 6063 have width dimensions of about 0.0036 inches,with a substantial portion of the strut elements in the remainingportions of the device 6050 having a width dimension of about 0.0027inches. In other exemplary implementations rail portions 6060 and 6061have width dimensions of about 0.0047 and rail portions 6062 and 6063have width dimensions of about 0.0036 inches, with the struts in adistal portion 6070 of device (illustrated with dashed lines) having awidth dimension of about 0.0023 inches and a majority of the remainingstruts having a width dimension of about 0.0027 inches. The reducedwidth dimension of distal portion 6070 produces a region of lower radialstrength that in smaller vessels or ducts minimizes surface interactionsbetween the distal portion 6070 and the vessel/duct to prevent orminimize the occurrence of damage to the vessel/duct wall while the clotretrieval device is proximally withdrawn from a patient.

Testing has shown the proximal taper region of the clot retrievaldevices 6050 to possess good force transmission characteristics alongwith good radial force characteristics that provide good sheathing andre-sheathing of the proximal taper portion into an introducer sheathand/or delivery catheter.

According to some implementations the clot retrieval devices 6050according to FIG. 31 are laser cut from a tube having an inner diameterof about 2.130 millimeters and a wall thickness of between about 0.104millimeters to about 0.128 millimeters. In use, a clot retrieval device6050 according to an implementation of that shown in FIG. 31 is advancedthrough the tortuous vascular anatomy or bodily duct of a patient to atreatment site in an unexpanded or compressed state of a first nominaldiameter and is movable from the unexpanded state to a radially expandedstate of a second nominal diameter greater than the first nominaldiameter for deployment at the treatment site. In alternative exemplaryembodiments the second nominal diameter (e.g., average diameter of mainbody portion) is about 3.0±0.5 millimeters. In some implementation, thedimensional and material characteristics of the cell structures 6080residing in the main body portion (section A) are selected to producesufficient radial force and contact interaction to cause the cellstructures 6080 to engage with an embolic obstruction residing in thevascular in a manner that permits partial or full removal of the embolicobstruction from the patient.

In some implementations the dimensional and material characteristics ofthe elements along the expandable length of the retrieval device areselected to produce a radial force per unit length of between about0.015 N/mm to about 0.035 N/mm when the outer diameter of the retrievaldevice is restrained to 1.5 millimeters. In some implementations thedimensional and material characteristics of the elements along theexpandable length are selected to produce a radial force per unit lengthof between about 0.017 N/mm to about 0.033 N/mm when the outer diameterof the retrieval device is restrained to 1.5 millimeters. Among the sameor alternative implementations, the dimensional and materialcharacteristics of the elements along the expandable length of theretrieval device are selected to produce a radial force of between about0.010 N/mm to about 0.020 N/mm when the nominal diameter of the mainbody portion is about 2.0±0.5 millimeters.

In the implementations of FIG. 31, many of the cell structures(excluding those that are formed at least in part by rail segments 6051and 6052) are shown having similar shapes with most of the cellstructure including a pair of short struts 6081 and a pair of longstruts 6082 that are joined by connector regions 6083. In exemplaryimplementations (as shown in FIGS. 32A-C), short struts 6081 have alinear length, L₁, of about 0.055±0.010 inches, long struts 6082 have alinear length, L₃, of about 0.128±0.010 inches and connector regions6083 have a linear length, L₃, of about 0.0371±0.010 inches. In one ormore implementations the cell structures 6080 have an area of about 4.5mm² to about 5.5 mm². In one exemplary implementation the cellstructures 6080 have an area of about 5.0 mm². In exemplaryimplementations the overall length of the expandable portion of the clotretrieval device is between about 25.0 millimeters and about 35.0millimeters with the main body portion (section A) having a length ofbetween about 10.0 millimeters and about 15.0 millimeters. In oneexemplary implementation the overall length of the expandable portion ofthe clot retrieval device is about 30.7 millimeters with the main bodyportion (section A) having a length of about 13.1 millimeters and theproximal and distal taper regions having a length of about 10.9millimeters and about 6.7 millimeters, respectively.

Turning now to FIG. 33A, an alternative implementation to the clotretrieval devices described above in conjunction with FIG. 30 isdepicted. FIGS. 33B and 33C illustrate exemplary three-dimensional topand side views of the clot retrieval devices 7000 of FIG. 33A. Sectionsof the treatment device 7000 that are generally identified as regions Eand G are in many respects similar, and in some instances the same, tothe same general regions of the clot retrieval devices 6000 describedabove. As an example, the width dimension of the struts generallylocated in region G may in different implementations take differentvalues to establish any of a variety of desired distal tapercharacteristics as disclosed above. In addition, region E may assume anyof a variety of implementations as previously disclosed above inconjunction with the retrieval devices of FIG. 30. As shown in FIG. 33A,the sizes of the cell structures 7002 generally located in a centralregion F of the device 7000 are larger than those in the implementationsof devices 6000 described above. An advantage of the decreased strutdensity in the central region F of device 7000 is that it enhances theintegration of an embolic obstruction/clot within region F of thedevice. In the treatment devices 7000 of FIG. 33, the larger cellstructures are created by the omission of selected long struts 6022 inthe device 6000 of FIG. 30 to create cell structures 7002 having areasthat are about double the size of cells 7024. In one implementation,cell structures 7020 have an area of between about 8.0 mm² and about 8.5mm². In one exemplary implementation cell structures 7020 have an areaof about 8.3 mm². It is important to note that any of a number of othermethods may be used to create the larger cell structures. A particularadvantage of the implementations of FIG. 33 is that good strut nestingcharacteristics are preserved to facilitate a low profile delivery stateof the device 7000.

A decrease in the strut density in a region generally results in a lowerradial strength within the region. In a clot retrieval device thisreduction can adversely affect the device's ability to integrate with anembolic obstruction/clot. To compensate for this reduction in radialstrength, in some implementations selective strut portions 7006 (denotedby dashed lines) generally located within region F of the retrievaldevices are provided with a width dimension greater than the widthdimension of strut portions 7004 (denoted by solid lines). In accordancewith some implementations the width dimensions of strut portions 7006are selected so that the over-all radial strength per unit length ofexpandable portion of the retrieval device is similar to that absent theremoval of struts to create the larger sized cell structures. As anexample, in the implementations described above where decreased strutdensity is achieved by the omission of certain long struts 6022 in adevice of FIG. 30, the width of struts 7006 are selected so that theover-all radial strength per unit length of the expandable portion ofthe retrieval device is similar to that of devices 6000 described above.For example, in some implementations strut portions 7004 have a widthdimension of about 0.0027 inches with strut portions 7006 having a widthdimension of about 0.0035 inches so that the over-all radial strengthper unit length of the expandable portion is similar to the same area ofthe retrieval devices 6000 having mostly unitary cell sizes and strutwidth dimensions of about 0.0027 inches.

Although not required, as illustrated in FIG. 33A, the transition ofstrut widths preferably occur at locations (denoted by “x”) other thanjunctions 7008. Although not required, the width transitions preferablycomprise tapers that provide a relatively smooth transition between thedifferent width dimensions.

Strut portions of enhanced width 7006 are one method of creating adesired over-all radial strength per unit length. Other methods are alsoavailable. For example, strut portions 7006 may instead have an enhancedthickness dimension over strut portions 7004, or may have a combinationof enhanced thickness and width dimensions. In other implementations thewidth dimension of a majority, substantially all or all of the strutsgenerally located in section F are enhanced to compensate for thereduction in strut density.

With reference to FIG. 34A, alternative implementations to the clotretrieval devices described above in conjunction with FIG. 30 aredepicted. FIGS. 34B and 34C illustrate exemplary three-dimensional topand side views of the clot retrieval devices 7020 of FIG. 34A. Sectionsof the treatment device 7020 that are generally identified as regions Eand G are in many respects similar, and in some instances the same, tothe same general regions of the clot retrieval devices 6000 describedabove. As an example, the width dimension of the struts in region G may,in different implementations, take different values to establish any ofa variety of desired distal taper characteristics as disclosed above. Inaddition, region E may assume any of a variety of implementations aspreviously disclosed above in conjunction with the retrieval devices ofFIG. 30. As shown in FIG. 34A, the sizes of some of the cell structures7022 in a central region J of the device 7020 are larger than those inthe implementations of devices 6000 described above to providecircumferentially extending zones of decreased strut density that aregenerally separated by circumferentially extending rows of non-enlargedcell structures 7024. In the treatment devices 7020 of FIG. 34, thelarger cell structures are created by the omission of selected longstruts 6022 in the device 6000 of FIG. 30 to create cell structures 7022having areas of about double in size. In one implementation cellstructures 7022 have an area of about 8.3 mm². It is important to notethat any of a number of other methods may be used to create the largercell structures. A particular advantage of the implementations of FIG.34 is that good strut nesting characteristics are preserved tofacilitate a low profile delivery state of the device 7020.

As discussed above, a decrease in the strut density in a regiongenerally results in a lower radial strength within the region. In aclot retrieval device this reduction can adversely affect the device'sability to integrate with an embolic obstruction/clot. To compensate forthis reduction in radial strength, selective strut portions 7026(denoted by dashed lines) generally located within region J of theretrieval devices are provided with a width dimension greater than thewidth dimension of strut portions 7025 (denoted by solid lines). Inaccordance with some implementations the width dimensions of strutportions 7026 are selected so that the over-all radial strength per unitlength of the expandable portion of the retrieval device is similar tothat absent the removal of struts to create the larger sized cellstructures. As an example, in the implementations described above wheredecreased strut density is achieved by the omission of certain longstruts 6022 in a device of FIG. 30, the width of struts 7026 areselected so that the over-all radial strength per unit length of theexpandable portion of the retrieval device is similar to that of devices6000 described above. For example, in some implementations strutportions 7025 have a width dimension of about 0.0027 inches with strutportions 7026 having a width dimension of about 0.0035 inches so thatthe over-all radial strength per unit length of the expandable portionof the retrieval device is similar to the same area of the retrievaldevices 6000 having mostly unitary cell sizes and strut width dimensionsof about 0.0027 inches. In some implementation the width of the struts7029 have a width dimension of between 0.0031 inches and about 0.0033inches similar to those previously discussed above with respect to someimplementations of device 6000.

In some implementations, as illustrated in FIG. 34A, the transition ofsome or all of the strut widths occur at locations other than junctions7028, while in other implementations the transition of some or all ofthe strut widths occur at locations other than junctions 7028. Althoughnot required, the width transitions preferably comprise tapers thatprovide a relatively smooth transition between the different widthdimensions.

Strut portions of enhanced width 7026 are one method of creating inregion J a desired over-all radial strength. Other methods are alsoavailable. For example, strut portions 7026 may instead have an enhancedthickness dimension over strut portions 7025, or may have a combinationof enhanced thickness and width dimensions.

With reference to FIG. 35A, an alternative implementation to the clotretrieval devices described above in conjunction with FIG. 30 isdepicted. FIGS. 35B and 35C illustrate exemplary three-dimensional topand side views of the clot retrieval devices 7050 of FIG. 35A. Sectionsof the treatment device 7050 that are generally identified as regions Eand G are in many respects similar, and in some instances the same, tothe same general regions of the clot retrieval devices 6000 describedabove. As an example, the width dimension of the struts generallylocated in region G may in different implementations take differentvalues to establish any of a variety of desired distal tapercharacteristics as disclosed above. In addition, region E may assume anyof a variety of implementations as previously disclosed above inconjunction with the retrieval devices of FIG. 30. As shown in FIG. 35A,the sizes of some of the cell structures 7052 in a central region K ofthe device 7050 are larger than those in the implementations of devices6000 described above to provide zones of decreased strut density thatare dispersed among non-enlarged cell structures 7054. In the treatmentdevices 7050 of FIG. 35, the larger cell structures are created by theomission of selected long struts 6022 in the device 6000 of FIG. 30 tocreate cell structures 7052 having areas of about double the size ofcells 7054. In one implementation the area of cell structures 7052 isabout 8.3 mm². It is important to note that any of a number of othermethods may be used to create the larger cell structures. A particularadvantage of the implementations of FIG. 35 is that good strut nestingcharacteristics are preserved to facilitate a low profile delivery stateof the device 7050.

As discussed above, a decrease in the strut density in a regiongenerally results in a lower radial strength within the region. In aclot retrieval device this reduction can adversely affect the device'sability to integrate with an embolic obstruction/clot. To compensate forthis reduction in radial strength, selective strut portions 7056(denoted by dashed lines) generally located within region K of theretrieval devices are provided with a width dimension greater than thewidth dimension of strut portions 7055 (denoted by solid lines). Inaccordance with some implementations the width dimensions of strutportions 7056 are selected so that the over-all radial strength per unitlength of the expandable portion of the retrieval device is similar tothat absent the removal of struts to create the larger sized cellstructures. As an example, in the implementations described above wheredecreased strut density is achieved by the omission of certain longstruts 6022 in a device of FIG. 30, the width of struts 7056 areselected so that the over-all radial strength per unit length of theexpandable portion of the retrieval device is similar to that of devices6000 described above. For example, in some implementations strutportions 7055 have a width dimension of about 0.0027 inches with strutportions 7056 having a width dimension of about 0.0035 inches so thatthe over-all radial strength per unit length of the expandable portionof the retrieval device is similar to the same area of the retrievaldevices 6000 having mostly unitary cell sizes and strut width dimensionsof about 0.0027 inches. In some implementations the width of the struts7059 have a width dimension of between 0.0031 inches and about 0.0033inches similar to those previously discussed above with respect to someimplementations of device 6000.

Although not required, as illustrated in FIG. 35A, the transition ofstrut widths preferably occur at locations other than junctions 7058.Although not required, the width transitions preferably comprise tapersthat provide a relatively smooth transition between the different widthdimensions.

Strut portions of enhanced width 7056 are one method of creating adesired over-all radial strength per unit length. Other methods are alsoavailable. For example, strut portions 7056 may instead have an enhancedthickness dimension over strut portions 7055, or may have a combinationof enhanced thickness and width dimensions.

FIG. 36 illustrates clot retrieval devices 6090 similar to those of FIG.30, with a difference in the size of the cell structures 6091 generallylocated in region B of the device. As illustrated in FIG. 36, cellstructures 6091 are of a greater size than the cell structures 6020 ofthe device shown in FIG. 30. As previously discussed, an advantage oflarger sized cell structures within the main body portion of theretrieval device is that it enhances clot integration into the main bodyportion when a radial strength of the main body portion is properlyprovided. For the purpose of providing sufficient radial strength inregion B of the device 6090, the struts 6092 (denoted by dashed lines)generally located within region B have an enhanced width dimension,which in one implementation is about 0.0035 inches. In oneimplementation the width dimension of the struts 6092 generally locatedin region B are similar to or the same as the width dimension of thedistal sections of rail segments 6001 and/or 6002 (e.g., having the sameor similar width dimension of one or more of struts 6009, 6010 and6011). Although not required, the transition in width dimensionspreferably occur at locations other than at junctions 6045, asillustrated in FIG. 36.

FIG. 37 illustrates clot retrieval devices 8000 according to otherimplementations where, among other features, the strut elements of railsegments 8001 and 8002 have varying width dimensions. FIG. 37 depicts aclot retrieval device in a two-dimensional plane view as if the devicewere cut and laid flat on a surface. FIG. 37 depicts the device in itsmanufactured (as-cut) configuration. In one implementation, rail segment8001 transitions from a maximum width dimension at or near its proximalend 8014 to a minimum width dimension at or near its distal end 8015. Ina like manner, rail segment 8002 transitions from a maximum widthdimension at or near its proximal end 8014 to a minimum width dimensionat or near its distal end 8016. As previously discussed, the widthdimensions of the rail segments are selected to enhance their ability todistribute forces and to resist buckling when a push force is applied tothe proximal end 8014 of the clot retrieval device. In someimplementations the percentage change between the maximum rail widthdimension and the minimum rail width dimension is between about 20.0%and about 35.0%. In other implementations the percentage change betweenthe maximum rail width dimension and the minimum rail width dimension isbetween about 25.0% and about 30.0%. In an exemplary implementation thewidth dimension of the rail segments transitions from a maximum widthdimension of about 0.0047±0.0004 inches to a minimum width dimension ofabout 0.0027±0.0004 inches. In another exemplary implementation thewidth dimension of the rail segments transitions from a maximum widthdimension of about 0.0047±0.0004 inches to a minimum width dimension ofabout 0.0034±0.0004 inches.

Although FIG. 37 represents rail segments that are devoid ofundulations, as previously described herein, it is appreciated that railsegments such as those shown in FIGS. 1A and 4A are also contemplated.Like the devices of FIG. 30 disclosed above, it is appreciated thatother than the rail width characteristics disclosed in the precedingparagraph, any of a number of the features and/or characteristics of thevascular treatment devices described in conjunction with the devices ofFIGS. 1-29 (e.g., dimensional, spatial, relational, etc.) may beincorporated into a clot retrieval device 8000 according to FIG. 37.

In some implementations the width of rails 8001 and 8002 taper alongtheir length (or a portion thereof) in a substantial uniform anddiminishing fashion. In some implementations discrete portions of therails have a substantially uniform width dimension with onlytransitional tapers being used to join rail portions of differentwidths. In some implementations discrete portions of the rails have asubstantially uniform width dimension with stepped transitions betweenrail portions of different widths. In other implementations two or moreof the preceding width transitional methods are utilized. Although notrequired, it is preferable that the width transitions occur at portionsalong the rail struts other than at a junction of the struts (e.g.,junctions 8030).

In some implementations, as previously described, struts 8012 and 8013of the most proximal cell structure 8018 also have an enhanced widthdimension that may be equal to or less than the maximum rail widthdimension for the purpose of enhancing the pushability of the clotretrieval device as it is advanced through the tortuous anatomy of apatient. In some implementations less than the entire length of struts8012 and 8013 are provided with an enhanced width dimension. Forexample, in some implementations an enhanced width portion extends froma proximal most end of struts 8012 and 8013 and terminates a distanceprior to their juncture. The configuration of struts 8012 and 8013 mayalso be altered in manners previously disclosed.

With continued reference to FIG. 37, in exemplary implementations all orportions of struts 8003 and 8004 (and optionally all or portions ofstruts 8005 and 8006) have width dimensions of about 0.0045 inches toabout 0.0050 inches, all or portions of struts 8007 and 8008 (andoptionally all or portions of struts 8005 and 8006) have widthdimensions of about 0.0036 inches to about 0.0040 inches, all orportions of struts 8009 and 8010 (and optionally all or portions ofstruts 8007 and 8008) have width dimensions of about 0.0034 inches toabout 0.0036 inches. In some implementations the remainder of the strutsgenerally located in region M of the device have width dimensions ofabout 0.0027 inches, the struts in region N have width dimensions ofabout 0.0034 inches to about 0.0036 inches, and the struts generallylocated in region O have a width dimension of about 0.0031 inches toabout 0.033 inches. In one or more of the immediately precedingimplementations, the width dimension of struts 8012 and 8013 is betweenabout 0.0036 inches and about 0.0047 inches. It is to be appreciatedthat the dimensions disclosed relate to exemplary implementations andare also subject to customary manufacturing tolerances. Variations inthe dimensions are also possible and contemplated.

Although not required, it is preferable that the width transitions occurat portions along the struts themselves other than at a junction of thestruts (e.g., junctions 8030 and 8032).

As illustrated in FIG. 37, the strut density in the region generallyidentified by “N” is notably less than the strut densities in theregions generally identified by “M” and “O”. As a consequence, the cellstructures 8020 generally located in region N are of a larger size thanthe cell structures 8021 generally located in regions N and O. Aspreviously discussed, an advantage of larger sized cell structureswithin the main body portion of the retrieval device is that it enhancesclot integration into the main body portion (region N) when a radialstrength of the main body portion is properly provided. For the purposeof providing sufficient radial strength in region N of the device, thestruts within region have an enhanced width dimension as compared to thecell struts generally residing in region M (other than the struts8003-8013) and the cell struts generally residing in region O. In oneimplementation the width dimension of the struts in region N are similarto or the same as the width dimension of the distal struts 8009, 8010and/or 8011 of rail segments 8001 and/or 8002.

In an exemplary implementation struts 8003-8006 have a width dimensionof about 0.0047 inches, struts 8007, 8008, and a proximal portion ofstrut 8010 have a width dimension of about 0.0040 inches, struts 8009,8011 and a distal portion of strut 8010 have a width dimension of about0.0034 inches, struts 8012-8013 have a width dimension of about 0.0040inches. In some implementations the remainder of the struts in region Mof the device have width dimensions of about 0.0027 inches, the strutsin region N have width dimensions of about 0.0034 inches, and the strutsin region O have a width dimension of about 0.0031 inches. The increasedwidth dimension of the struts in section O advantageously reduces thelikelihood of struts buckling within the distal taper region of the clotretrieval device during its delivery to a treatment site of a patient.The increased width dimension also increases the radial strength of thedistal taper region that enhances the ability of the distal taper regionto remain open while the clot retrieval device is withdrawn from apatient so that it may sweep away remaining portions of the clot whenthe clot retrieval device is being withdrawn from the patient.

According to some implementations the clot retrieval devices 8000according to FIG. 37 are laser cut from a tube having an inner diameterof about 3.77 millimeters and a wall thickness of between about 0.097millimeters to about 0.131 millimeters. In use, a clot retrieval device8000 according to an implementation of that shown in FIG. 37 is advancedthrough the tortuous vascular anatomy or bodily duct of a patient to atreatment site in an unexpanded or compressed state of a first nominaldiameter and is movable from the unexpanded state to a radially expandedstate of a second nominal diameter greater than the first nominaldiameter for deployment at the treatment site. In alternative exemplaryembodiments the second nominal diameter (e.g., average diameter of mainbody portion) is about 5.5±0.5 millimeters. In some implementation, thedimensional and material characteristics of the cell structures 8020residing in the main body (section N) are selected to produce sufficientradial force and contact interaction to cause the cell structures 8020to engage with an embolic obstruction/clot residing in the vascular in amanner that permits partial or full removal of the embolic obstructionfrom the patient.

In some implementations the dimensional and material characteristics ofthe elements along the expandable length of the retrieval device areselected to produce a radial force per unit length of between about0.040 N/mm to about 0.065 N/mm when the outer diameter of the retrievaldevice is restrained to 1.5 millimeters. In some implementations thedimensional and material characteristics of the elements along theexpandable length are selected to produce a radial force per unit lengthof between about 0.045 N/mm to about 0.060 N/mm when the outer diameterof the retrieval device is restrained to 1.5 millimeters. In someimplementations the dimensional and material characteristics of theelements along the expandable length are selected to produce a radialforce per unit length of between about 0.050 N/mm to about 0.060 N/mmwhen the outer diameter of the retrieval device is restrained to 1.5millimeters. In some implementations the dimensional and materialcharacteristics of the elements along the expandable length are selectedto produce a radial force per unit length of between about 0.049 N/mm toabout 0.057 N/mm when the outer diameter of the retrieval device isrestrained to 1.5 millimeters. Among the same or alternativeimplementations, the dimensional and material characteristics of theelements along the expandable length of the retrieval device areselected to produce a radial force of between about 0.010 N/mm to about0.020 N/mm when the nominal diameter of the main body portion is about4.5±0.5 millimeters.

In the implementations of FIG. 37, the cell structures in regions M andO (excluding those that are formed at least in part by rail segments8001 and 8002) are shown having similar shapes with the cell structures8021 including a pair of short struts 8022 and a pair of long struts8024. In exemplary implementations the area of cell structures 8021 isbetween about 4.5 mm² and about 5.5 mm². In one exemplary implementationthe area of cell structures 8021 is about 5.0 mm² to about 5.2 mm². Thecell structures 8020 generally located in region N, in oneimplementation, comprise a shape consisting of two adjoining cellstructures 8021 with a long strut 8024 being omitted between them.Although other types of large sized cell structures are contemplated, anadvantage of the cell construction illustrated in FIG. 37 is that itpossesses good nesting capability to permit the retrieval device toachieve a small delivery profile.

In some implementations the overall length of the expandable portion ofthe clot retrieval device is between about 55.0 millimeters and about65.0 millimeters with the main body portion (section N) having a lengthof between about 25 millimeters and about 35.0 millimeters and theproximal and distal taper regions having a length of between about 10.0to about 20.0 millimeters. In one exemplary embodiment the overalllength of the expandable portion of the clot retrieval device is about58.4 millimeters with the main body portion (section N) having a lengthof about 29.3 millimeters and the proximal and distal taper regionshaving a length of about 16.6 millimeters and 12.5 millimeters,respectively.

FIG. 38 illustrates clot retrieval devices 8500 according to otherimplementations where, among other features, the strut elements of railsegments 8051 and 8052 have varying width dimensions. FIG. 38 depicts aclot retrieval device in a two-dimensional plane view as if the devicewere cut and laid flat on a surface. FIG. 38 depicts the device in itsmanufactured (as-cut) configuration. In one implementation, rail segment8051 transitions from a maximum width dimension at or near its proximalend 8066 to a minimum width dimension at or near its distal end 8067. Ina like manner, rail segment 8052 transitions from a maximum widthdimension at or near its proximal end 8066 to a minimum width dimensionat or near its distal end 8068. As previously discussed, the widthdimensions of the rail segments are selected to enhance their ability todistribute forces and to resist buckling when a push force is applied tothe proximal end 8064 of the clot retrieval device. In someimplementations the percentage change between the maximum rail widthdimension and the minimum rail width dimension is between about 20.0%and about 35.0%. In other implementations the percentage change betweenthe maximum rail width dimension and the minimum rail width dimension isbetween about 22.0% and about 27.0%. In an exemplary implementation thewidth dimension of the rail segments transitions from a maximum widthdimension of about 0.0047±0.0004 inches to a minimum width dimension ofabout 0.0035±0.0004 inches.

Although FIG. 38 represents rail segments that are devoid ofundulations, as previously described herein, it is appreciated that railsegments such as those shown in FIGS. 1A and 4A are also contemplated.Like the devices of FIG. 30 disclosed above, it is appreciated thatother than the rail width characteristics disclosed in the precedingparagraph, any of a number of the features and/or characteristics of thevascular treatment devices described in conjunction with the devices ofFIGS. 1-29 (e.g., dimensional, spatial, relational, etc.) may beincorporated into a clot retrieval device 8050 according to FIG. 38.

In some implementations the width of rails 8051 and/or 8052 taper alongtheir length (or a portion thereof) in a substantial uniform anddiminishing fashion. In some implementations discrete portions of therails have a substantially uniform width dimension with onlytransitional tapers being used to join rail portions of differentwidths. In some implementations discrete portions of the rails have asubstantially uniform width dimension with stepped transitions betweenrail portions of different widths. In other implementations two or moreof the preceding width transitional methods are utilized. Although notrequired, it is preferable that the width transitions occur at portionsalong the rail struts other than at a junction of the struts (e.g.,junctions 8070).

In some implementations, in a manner previously described, struts 8064and 8065 of the most proximal cell structure also have an enhanced widthdimension that may be equal to or less than the maximum rail widthdimension for the purpose of enhancing the pushability of the clotretrieval device as it is advanced through the tortuous anatomy of apatient. In some implementations less than the entire length of struts8064 and 8065 are provided with an enhanced width dimension. Forexample, in some implementations an enhanced width portion extends froma proximal most end of struts 8064 and 8065 and terminates a distanceprior to their juncture. The configuration of struts 8064 and 8065 mayalso be altered in manners previously disclosed.

With continued reference to FIG. 38, in exemplary implementations all orportions of struts 8053 and 8054 (and optionally all or portions ofstruts 8055 and 8056) have width dimensions of about 0.0045 inches toabout 0.0050 inches, all or portions of struts 8057 and 8058 (andoptionally all or portions of struts 8055, 8056, 8059 and 8060) havewidth dimensions of about 0.0036 inches to about 0.0040 inches, all orportions of struts 8059 and 8060 (and optionally all or portions ofstruts 8061, 8062 and 8063) have width dimensions of about 0.0034 inchesto about 0.0036 inches. In some implementations the remainder of thestruts generally located in region P of the device have width dimensionsof about 0.0027 inches, the struts generally located in region Q havewidth dimensions of about 0.0034 inches to about 0.0036 inches, and thestruts generally located in region R have a width dimension of about0.0031 inches to about 0.033 inches. In one or more of the immediatelypreceding implementations, the width dimension of struts 8064 and 8065is between about 0.0036 inches and about 0.0047 inches. It is to beappreciated that the dimensions disclosed relate to exemplaryimplementations and are also subject to customary manufacturingtolerances. Variations in the dimensions are possible and contemplated.

Although not required, it is preferable that the width transitions occurat portions along the struts themselves other than at a junction of thestruts (e.g., junctions 8070 and 8071).

As illustrated in FIG. 38, the strut density in the region generallyidentified by “Q” is notably less than the strut densities in theregions generally identified by “P” and “R”. As a consequence, the cellstructures 8080 generally located in region Q are of a larger size thanthe cell structures 8081 generally located in regions P and R. Aspreviously discussed, an advantage of larger sized cell structureswithin the main body portion of the retrieval device is that it enhancesclot integration into the main body portion (region Q) when a radialstrength of the main body portion is properly provided. For the purposeof providing sufficient radial strength in region Q of the device, thestruts generally located within region Q have an enhanced widthdimension as compared to the cell struts generally located in region P(other than the struts 8053-8065) and the cell struts generally locatedin region R. In one implementation the width dimension of the struts inregion Q are similar to or the same as the width dimension of the distalsections of rails 8051 and 8052 (e.g., struts 8061, 8062 and/or 8063).

In an exemplary implementation struts 8003-8006 and a proximal portionof struts 8055 and 8056 have a width dimension of about 0.0047 inches,struts 8057, 8058, and a distal and proximal portions of struts8055,8056 and 8059,8060, respectively, have a width dimension of about0.0040 inches, struts 8009, 8011 and a distal portion of strut 8010 havea width dimension of about 0.0034 inches, struts 8012-8013 have a widthdimension of about 0.0040 inches, struts 8061, 8062, 8063 and the distalportions of struts 8059 and 8060 have a width dimension of about 0.0035inches. In some implementations the remainder of the struts generallylocated in region P of the device have width dimensions of about 0.0027inches, the struts generally located in region Q have width dimensionsof about 0.0035 inches, and the struts generally located in region Rhave a width dimension of about 0.0031 inches. The increased widthdimension of the struts in section R advantageously reduces thelikelihood of struts buckling within the distal taper region of the clotretrieval device during its delivery to a treatment site of a patient.The increased width dimension also increases the radial strength of thedistal taper region that enhances the ability of the distal taper regionto remain open while the clot retrieval device is withdrawn from apatient so that it may sweep away remaining portions of the clot whenthe clot retrieval device is being withdrawn from the patient.

According to some implementations the clot retrieval devices 8050according to FIG. 38 are laser cut from a tube having an inner diameterof about 3.77 millimeters and a wall thickness of between about 0.097millimeters to about 0.131 millimeters. In use, a clot retrieval device8050 according to an implementation of that shown in FIG. 38 is advancedthrough the tortuous vascular anatomy or bodily duct of a patient to atreatment site in an unexpanded or compressed state of a first nominaldiameter and is movable from the unexpanded state to a radially expandedstate of a second nominal diameter greater than the first nominaldiameter for deployment at the treatment site. In alternative exemplaryembodiments the second nominal diameter (e.g., average diameter of mainbody portion) is about 6.0±0.5 millimeters. In some implementation, thedimensional and material characteristics of the cell structures 8080residing in the main body (section Q) are selected to produce sufficientradial force and contact interaction to cause the cell structures 8080to engage with an embolic obstruction/clot residing in the vascular in amanner that permits partial or full removal of the embolic obstructionfrom the patient. In some implementation, the dimensional and materialcharacteristics are selected to produce a radial force per unit lengthin the expandable portion of the retrieval device of between about 0.010N/mm to about 0.020 N/mm when the diameter of the main body portion isreduced to about 5.0±0.5 millimeters.

In the implementations of FIG. 38, the cell structures generally locatedin regions P and R (excluding those that are formed at least in part byrail segments 8051 and 8052) are shown having similar shapes with thecell structures 8081 including a pair of short struts 8082 and a pair oflong struts 8084. In an exemplary implementation the area of cellstructures 8081 is about 9.2 mm². The cell structures 8080 generallylocated in region Q, in one implementation, comprise a shape consistingof two adjoining cell structures 8081 with a long strut 8084 beingomitted between them. Although other types of large sized cellstructures are contemplated, an advantage of the cell constructionillustrated in FIG. 38 is that it possesses good nesting capability topermit the retrieval device to achieve a small delivery profile.

In some implementations the overall length of the expandable portion ofthe clot retrieval device is between about 65.0 millimeters and about75.0 millimeters with the main body portion (section Q) having a lengthof between about 25.0 millimeters and about 35.0 millimeters. In oneexemplary implementation the overall length of the expandable portion ofthe clot retrieval device is about 71.9 millimeters with the main bodyportion (section Q) having a length of about 32.3 millimeters and theproximal and distal taper regions having a length of about 22.5millimeters and 17.1 millimeters, respectively.

FIG. 39 depicts a two dimensional view of a duct obstruction retrievaldevice 370 according to another implementation. As with some of theother implementations previously described, the retrieval device 370comprises a proximal tapered end portion 371, a cylindrical main bodyportion 372 and a distal tapered end portion 373. A difference in thedistal tapered end portion 373 as compared to the distal tapered endportions previously described is that the distal tapered end portion 373has less than three full rows of cell structures so as to reduce thedistal taper length. In the example of FIG. 39 the distal tapered endportion comprises two full rows of cell structures 374 and 375 and apartial row of cell structures 376. (For the sake of clarity, althoughrow 375 in the implementation of FIG. 39 includes a single cellstructure, it is in any case considered a row of cell structures.) Theinclusion of a distal tapered end portion in the retrieval device thatculminates into a distal antenna provides a number of advantages overretrieval devices that would otherwise terminate in a blunt end. Oneadvantage is that once the retrieval device has been positioned andexpanded in a vessel of a patient the tapered end provides a greaterdegree of placement adjustment over a retrieval device having a bluntend. Another advantage is that the distal tapered end portion is moreatraumatic than a blunt end. The reduced taper length achieved bylimiting the construction of the distal tapered end portion 373 to lessthan three full rows of cell structures has been found to advantageouslyresult in a distal taper that is both more stable and more atraumaticthan those having a greater number of full rows of cell structures. Inretrievers having cell structures of different sizes, like those of cellstructures 376 and 377, it is preferable that the full rows of cells inthe distal tapered end portion 373 be comprised of substantially allsmall-sized cell structures 377 like that shown in FIG. 39.

According to some implementations the length of the distal tapered endportion 373 in the as-cut manufactured state is less than about 30% ofthe length of the main body portion 372, and preferably less than about25% of the length of the main body portion 372. In one implementationthe lengths of the main body portion 372 and the distal tapered endportion 373 are about 26 mm and 6 mm, respectively. In anotherimplementation the distal tapered end portion 373 has a length ofbetween about 4.5 mm to about 5.0 mm. According to some implementationsthe combined length of the distal tapered end portion 373 and the distalantenna 379 is less than about 10 mm.

FIG. 40A shows a two dimensional view of a duct obstruction retrievaldevice 380 according to another implementation Like the retrieval device370 shown in FIG. 39, retriever 380 comprises a distal tapered endportion comprising less than three full rows of cell structures.Retriever device 380 differs from retriever 370 in that the distaltapered end portion comprises cell structures that are bifurcated into afirst set of cell structures 386 and a second set of cell structures 387with the first cell of cell structures 386 terminating at a first distalantenna 388 and the second set of cell structures 387 terminating at asecond distal antenna 389. FIG. 40B depicts a three dimensional view ofretrieval device 380 with the reference number 383 denoting the distaltapered end portion of the device. As shown in FIG. 40B, distal antenna388 and distal antenna 389 are joined to form a retrieval device havinga distal tapered end portion with a closed end.

It is important to note that although the retrieval devices 370 and 380have been described as comprising distal antennas, in otherimplementations like retrieval devices are provided without distalantennas. The same applies to each of the implementations disclosed andcontemplated herein. In addition, with reference to the retrieval device380 of FIG. 40, in another implementation only a single distal antennais provided that is chosen between distal antenna 388 and distal antenna389. In such an implementation the retrieval device would possess anopen distal end with the second set of cell structures 387 beingavailable to sweep along the treatment vessel to capture dislodgedmaterial.

FIG. 41 is a two dimensional view of a duct obstruction retrieval device390 according to another implementation that comprises a distal taperedend portion comprising less than three full rows of cell structures.Like retrieval device 380, the distal tapered end portion of retrievaldevice 390 has cell structures that are bifurcated into a first set ofcell structures 396 and a second set of cell structures 397 with thefirst cell of cell structures 396 terminating at a first distal antenna398 and the second set of cell structures 397 terminating at a seconddistal antenna 399. As shown in FIG. 41, the first and second distalantennas 398 and 399 are longitudinally off-set from one another. In oneimplementation a radiopaque material, feature (e.g., flared strut) orcomponent (e.g., a coil) is positioned on each of the first and secondantennas. By virtue of there off-set construction, a radiopaquecomponent, for example, on each of the antennas enables the distal endof the retrieval device and the distal tapered end portion of theretrieval device to be visually delineated during the treatmentprocedure.

FIG. 42A is a two dimensional view of a duct obstruction retrievaldevice 450 according to another implementation. The retrieval device 450comprises an expandable member that has a proximal tapered end portion451, a cylindrical main body portion 452 and a distal tapered endportion 453. The outer-most cell structures in the proximal tapered endportion have outer wall segments that form first and second railsegments 454 and 455, respectively. Each of the rail segments 454 and455 extend from a proximal-most end of the expandable member to aposition at or near the proximal end of the cylindrical main bodyportion 452. In the implementation of FIG. 42, each of the rail segments454 and 455 are undulating. A proximal antenna 457 extends proximallyfrom a proximal-most cell structure 456.

The proximal-most cell structure 456, as shown in greater detail in FIG.42B, comprises first and second outer struts 460 and 461, respectively,and first and second inner struts 462 and 463, respectively. As shown inthe layout of FIG. 42B, the first outer strut 460 and a first portion461 a of the second outer strut 461 are straight in the two dimensionallayout while the first inner strut 462, second inner strut 463 and thesecond portion 461 b of strut 461 are curvilinear in the two dimensionallayout. In the manufactured, three dimensional configuration the firstouter strut 460 and the first portion 461 a of the second outer strut461 are curved and devoid of undulations. As a result of being orientedat the proximal end of the expandable member and being co-extensive tothe proximal antenna, the straight strut segments of the proximal-mostcell structure 456 enhance the pushability of the retrieval device 450as it is delivered through the anatomy of a patient as compared toretrieval devices having proximal-most cell structure with only curvedstruts in the two dimensional layout.

In some implementations, the total length of struts 460 and 462 (L1) andthe total length of struts 461 and 463 (L2) are substantially the samein order to promote a nesting of the struts when the expandable membertransitions from the expanded state to the unexpanded state. Accordingto some implementations the difference in length between L1 and L2 isless than 5.0%, while in other implementations the difference in lengthbetween L1 and L2 is less than 1.0%.

FIG. 43 illustrates a variation of the proximal-most cell structure 456.As depicted, each of struts 460 and 461 have an area of reduced width464 and 465, respectively, that are located adjacent their junction 466with the proximal antenna 457. The inclusion of the reduced width areas464 and 465 locally enhances the proximal-most cell structure's abilityto collapse by reducing the amount of force needed to initiate andeffectuate the collapse. Thus, for example, when the retrieval device450 is first introduced into an introducer sheath for placement within adelivery catheter or is withdrawn into a delivery catheter after theexpandable member has deployed inside a patient, the areas of reducedwidth 464 and 465 cause the struts 460 and 461 to be more easily foldedin the area of the junction 466 with less force than would otherwise berequired absent the areas of reduced width. This makes the retrievaldevice 450 more manageable when being handled by healthcareprofessionals when the retrieval device 450 is being introduced into thedelivery catheter for the first time, thus reducing the likelihood ofthe retrieval device being damaged during the introduction process. Aspreviously discussed, after the retrieval device 450 has been introducedand expanded inside the duct of a patient there may be occasions whenthe retrieval device is proximally withdrawn back into the deliverycatheter. This may occur, for example, upon the retrieval device beingimproperly placed in the duct or upon the completion of a retrievalprocedure. In each of these instances because less force is required tocollapse the expandable member of the retrieval device severaladvantages are realized. One advantage is that it reduces the likelihoodof the retrieval device 450 acting upon the delivery catheter in amanner that would cause an inadvertent displacement of the deliverycatheter within the duct of the patient. Another advantage is that itreduces the likelihood of excessive force being applied at theattachment between the proximal antenna 457 and the elongate wire (e.g.elongate wire 40 shown in FIG. 1A) that would result in a failure at thejunction.

In the implementation of FIG. 43 the areas of reduced width 464 and 465comprise tapers. In other implementations the areas of reduced width aredenoted by a stepped reduction in strut width. The amount by which thewidth is reduced in areas 464 and 465 will vary according to the nominalwidths of struts 460 and 461. In any event, it is important that theamount of width reduction is consistent with the radial force andstructural integrity requirements of the expandable member. It has beendiscovered that a reduction of width in the as-cut manufactured state ofbetween about 5.0% and about 20.0% is suitable for struts having anominal width of between about 0.0057 inches and about 0.0027 inches,with a preferable range being between about 10.0% and about 20.0% inwidth reduction. In one implementation the width dimension W1 of struts460 and 461 is about 0.0053 inches with the minimum width dimension ofthe areas of reduced width being 0.0047 inches. In anotherimplementation the width dimension W1 of struts 460 and 461 is about0.0057 inches with the minimum width dimension of the areas of reducedwidth being 0.0046 inches.

In some implementations the as-cut width dimensions of struts 460 and461 are different, with the width dimension of their respective areas ofreduced width 464 and 465 also being different. For example, in oneimplementation strut 460 has a width dimension of about 0.0050 inches,strut 461 has a width dimension of about 0.0057 inches, and areas ofreduce width 464 and 465 have width dimensions of about 0.0042 inchesand about 0.0046 inches, respectively.

FIG. 44 shows another variation of the proximal-most cell structure 457wherein outer struts 460 and 461 comprise a proximal section 467, amidsection 468 and a distal section 469. Because the width dimensions ofthe outer struts 460 and 461 of the proximal-most cell structure 456 aregenerally made greater than most of struts in the remaining portion ofthe retrieval device 450 for the purpose of enhancing the pushability ofthe expandable member, the bulk of material at the junctures 471 and 472located at the distal end of the struts may impede the expandablemember's ability to collapse. For this reason, in the implementation ofFIG. 44 the distal sections 469 have a reduced width dimension in orderto reduce the amount of material occupying the juncture regions 471 and472. Although FIG. 44 also shows the proximal sections 467 having areduced width dimension (similar to that described above), in someimplementations this is not the case. In a manner described above, thesections of reduced width may comprise tapers and/or steps.

Another advantage of the implementation depicted in FIG. 44 is that themidsection 468 of struts 460 and 461 may be provided with a sufficientwidth to enhance the visibility of the device under fluoroscopy withoutmaterially impacting the ability of the proximal end of the proximaltapered region 451 to collapse or to otherwise assume its unexpandedstate. According to one implementation the width dimension of the strutmidsections 468 is about 0.0053 inches and the minimum width dimensionof the proximal and distal sections 467 and 469 being 0.0047 inches and0.0041 inches, respectively. As with some of the FIG. 43implementations, in some FIG. 44 implementations the width dimensions ofstruts 460 and 461 are different, with the width dimension of one ormore of their respective proximal sections, midsections and distalsections being different.

FIG. 45A is a two dimensional view of a duct obstruction retrievaldevice 800 according to another implementation. The retrieval device 800comprises an expandable member that has a proximal tapered end portion801, a cylindrical main body portion 802 and a distal tapered endportion 803. The outer-most cell structures in the proximal tapered endportion have outer wall segments that form on one side a non-undulatingrail segment 804 and on the other side an undulating rail segment 805.Each of the rail segments 804 and 805 extend from a proximal-most end ofthe expandable member to a position at or near the proximal end of thecylindrical main body portion 802. A proximal antenna 806 extendsproximally from a proximal-most cell structure 807 while a distalantenna 808 extends distally from the distal end of distal taperedsection 803. The distal tapered section 803 is similar to that describedabove in conjunction with FIG. 39. In some implementations theproximal-most cell structure 807 has the same features andcharacteristics as proximal-most cell structure 456 in theimplementations of FIGS. 42-44 above.

As a result of the diagonal disposition of the cell structures in theretrieval device, the straight line length along which rails 804 and 805pass are different in the as-cut manufactured state with the straightline length that passes along rail 804 being longer than the straightline length that passes along rail 805. The linear configuration of rail804 in combination with the undulating configuration of rail 805advantageously results in the rails 804 and 805 having lengths that moreclosely approach one another when the retrieval device assumes itsunexpanded/delivery state. According to one implementation, rails 804and 805 are configured to achieve substantially the same length when theretrieval device 800 is in the unexpanded/delivery state. In someimplementations, the difference in length between rails 804 and 805 isbetween about 0% to about 5% when the retrieval device 800 is in theunexpanded/delivery state.

As discussed earlier, the retrieval devices disclosed and contemplatedherein are generally laser cut from a tube and in their actual threedimension configuration generally comprise tube like structures. FIG.45, like many of the other figures, represents a retrieval device as itwould appear in a two dimension layout, that is, as if it were cut alongits length and laid out on a flat surface. With this in mind, and withreference to FIG. 45B, in the two dimension layout the cell structuresare polygons comprising a plurality of struts. As shown, rail segments804 and 805 are constructed by the outer walls of the outer most cellstructures 807, 810 and 811 in the proximal tapered section 810.Undulating rail segment 805 is formed by a first outer wall 812 of theproximal-most cell structure and the outer walls 814 of outer cellstructures 810, whereas the non-undulating rail segment 804 is formed bya second outer wall 813 of the proximal-most cell structure and theouter walls 815 of outer cell structures 811. As represented in FIG.45B, in the two dimension layout the outer walls 814 are curvilinear andthe outer walls 815 are straight. As will be appreciated, when in thetubular form, the rail 804 will be curved when the expandable memberassumes an expanded state, but will nonetheless be devoid ofundulations. Rail 805 will also assume an additional degree of curvaturein its three dimensional state, but unlike rail 804 will compriseundulations.

An advantage of the proximal tapered section 801 design is that thenon-undulating rail segment 804 provides the aforementioned benefitsrelated to pushability and kink resistance, while the undulating railsegment 805 accommodates the inclusion of a larger number ofsymmetric-shaped polygons and/or nearly symmetric-shaped polygons withinthe section 801. The inclusion of an increased number ofsymmetric-shaped and/or nearly symmetric-shaped polygons in the distaltapered end portion 801 improves its ability to assume it's unexpandedor compressed state and also provides for a more uniform and compactconfiguration. Because symmetrically shaped cell structures have betternesting tendencies than their non-symmetric counter-parts, theaforementioned advantages are achieved, at least in part, by theincreased number of symmetrically shaped cell structures disposed withinthe proximal tapered end portion 801.

Another advantage of a proximal tapered end portion having onenon-undulating rail segment 804 and one undulating rail segment 805 isthat the inclusion of the undulating rail segment provides more freedomin the design of the cell structures within the proximal tapered endportion as opposed to a design having two non-undulating rails. As shownin FIG. 45B, the outer cell structures 811, along which thenon-undulating rail segment 804 is formed, comprise structures that areconsiderably more symmetric than those, like for example, shown in FIG.30.

With reference to FIG. 45C, according to one implementation theretriever device 800 has the following as-cut dimensionalcharacteristics: L1=56.44 mm±0.50 mm; L2=26.85 mm±0.50 mm; L3=2.0 mm±0.1mm; L4=4.0 mm±0.3 mm; W 1=0.0054 inches±0.0004 inches; W2=0.0056inches±0.0004 inches; W3=0.0047 inches±0.0004 inches; W4=0.0047inches±0.0004 inches; W5=0.0040 inches±0.0004 inches; W6=0.0027inches±0.0004 inches; W7=0.0034 inches±0.0004 inches; W8=0.0031inches±0.0004 inches; W9=0.010 inches±0.007 inches; W10=0.0035inches±0.0004 inches; W11=0.0025 inches±0.0004 inches. In oneimplementation the length of the proximal tapered end portion and thedistal tapered end portion is about 13 mm and 7 mm, respectively.

FIG. 46 illustrates an obstruction retrieval device 830 according toanother implementation wherein portions 833 of some struts 832 in thedistal tapered end portion 831 of the retriever device are flared toenhance the radiopacity of the distal region of the device. In someimplementations during manufacture each of portions 833 are laser cut soas to possess an enhanced width dimension with respect to the remainderof strut 832. Besides in themselves enhancing radiopacity, the flaredportions (or portions of enhanced width) provide a good platform forreceiving a radiopaque coating such as, for example, a gold coating. Inthe implementation of FIG. 46 the flared portions 88 are positioned asufficient distance from the strut junctions 834 so as to not interferewith the retriever's ability to compress. In the implementation of FIG.46 the flared portions 833 are also longitudinally staggered so thatwhen the retriever 830 is in the compressed state no more than a singleflared portion 833 will occupy a longitudinal position. Such aconfiguration lessons the impact the flared portions 833 may have on theretriever's lowest achievable diameter dimension along the distaltapered end portion 831. In the embodiment of FIG. 46, the flaredportions comprise nodes which in one implementation have a diameter ofabout 0.015 inches. In other embodiments the flared portions 833 arelongitudinal in nature and occupy a substantial length of the struts832. In such implementations the flared portions 833 may have a width ofbetween about 0.0035 inches to about 0.0045 inches.

FIGS. 47A and 47B illustrate a distal segment of an obstructionretrieval device 480 according to one implementation. FIG. 47A depictsthe device 480 in a two-dimensional layout as if it were cut along itslength and laid out on a flat surface. While FIG. 47A depicts the device480 in its as-cut configuration, the three-dimensional representation ofFIG. 47B shows the device 480 in a post-cut manufactured state.

With reference to FIG. 47A, the distal segment of device 480 comprises aplurality of distal cell structures 488-491 with a set of antennas 481,482 and 483 extending distally from the junction regions 492-494 of cellstructures 488-491. In some implementations tabs 485-487, or otherenhanced dimension features, are provided at one or more ends of thedistal most cell structures for the purpose of identifying the distalend of the device under fluoroscopy by virtue of their enhanceddimensional characteristics and/or as a result of being endowed with aradiopaque material. As shown in FIG. 47A, in some implementations thedistal-most cell structures are smaller than the adjacent cellstructures in the main body portion of the device 480.

As shown in FIG. 47B, at a point in time after the device 480 has beenformed, such as being cut by a laser, the distal ends of antennas 481,482 and 483 are joined together at the juncture 484 so as to provide theinternal cavity of device 480 with a closed-end. In effect, theclosed-end forms a basket that facilitates the collection ofparticulates, such as embolic material, that may become dislodged duringa retrieval procedure. In some implementations the juncture 484 isformed by soldering together the distal ends of the antennas 481-483. Insome implementations the distal ends of the antennas 481-483 arepositioned within an encasement, such as a coil spring or otherperforated structure, with a solder or other bonding agent being appliedwithin and/or about the encasement to effectuate a bonding together ofthe distal ends of the antennas 481-483. In some implementations theencasement comprises a rounded atraumatic distal tip. In someimplementations the encasement comprises a radiopaque material.

FIGS. 48A and 48B illustrate an obstruction retrieval device 850according to one implementation. FIG. 48A depicts the device 850 in atwo-dimensional layout as if it were cut along its length and laid outon a flat surface. While FIG. 48A depicts the device 850 in its as-cutconfiguration, the three-dimensional representation of FIG. 48B showsthe device 480 in a post-cut manufactured state. The device includes aproximal antenna 851, a proximal taper portion 852, a main body portion853 and a distal portion 855. In the as-cut manufactured state the mainbody portion 853 and the distal portion 855 have the same, orsubstantially same, diameter. At a point in time after the device 850has been cut, such as by laser cutting, the device 850 is formed so thatthe unconstrained configuration of the distal portion 855 has a diameterthat is greater than that of the unconstrained main body portion 853.The post as-cut form of the device 850 may be achieved with the use ofmandrels or other tools and methods known in the art. In someimplementation the ratio of the unconstrained diameter of the distalportion 855 (absent the transition portion 854) and the main bodyportion 853 is between about 1.2/1.0 and about 2.0/1.0. For example,according to one implementation the average unconstrained diameter ofthe main body portion 853 is about 2.0 millimeters and the averageunconstrained diameter of the distal portion 855, absent the transitionportion 864, is about 4.0 millimeters. According to some implementationsthe ratio of the unconstrained length of the distal portion 855 (absentthe transition portion 854) and the unconstrained length of the mainbody portion is between about 0.2 to about 0.7. For example, accordingto one implementation the unconstrained length of the main body portion855 is between about 15 to 25 millimeters and the unconstrained lengthof the distal portion (absent the transition portion 854) is betweenabout 5 to 10 millimeters.

According to some implementations, as depicted in FIG. 48A, the cellstructures in the main body portion 853 are larger in size than those inthe distal portion 855. The lower strut density in the main body portion853 facilitates an integration of the retrieval device 850 within anobstruction. The higher strut density in the distal portion 855facilitates the entrapment of dislodge particles as discussed in moredetail below. Additionally, in some implementations the retrieval deviceis constructed in a manner that results in a radial force being exertedby the main body portion 853 that is greater than the radial forceexerted by the distal portion 855 when the retrieval device 850 isdeployed within a duct of a patient. In such an implementation, the mainbody portion 853 is situated to capture an obstruction while the distalportion 855 more gently acts against a wall of the duct distal to theobstruction to entrap portions of the obstruction that become dislodgedduring and after its capture. As such, according to one method theretrieval device 850 is placed at the treatment site of a patient by useof a delivery catheter, as previously disclosed herein. The retrievaldevice 850 is positioned at a distal end of the delivery catheter sothat the main body portion 853 is positioned at the site of theobstruction to be retrieved. When sheathed within the delivery catheterthe main body portion 853 and the distal portion 855 have the same, orsubstantially the same, diameter. Thereafter, the delivery catheter iswithdrawn proximally to cause the constrained retrieval device to expandat the treatment site so that the main body portion 853 is at leastpartially forced into the obstruction and so that at least a portion ofthe distal portion 855 more gently rests against the duct wall distal tothe obstruction. Upon the obstruction being captured within the mainbody portion 853 of device 850, the device may be removed from thepatient in a manner consistent with one or more of the methodspreviously disclosed herein. During such removal, as the retrievaldevice is pulled proximally the distal portion 855 sweeps along the ductwall to entrap portions of the obstruction that may have becomedislodged. By virtue of its enhanced diametric dimension, the distalportion 855 maintains contact with the duct wall during all or a portionof the removal procedure.

As discussed above, a lower strut density in the main body portion 853facilitates an integration of the retrieval device 850 within anobstruction. However, in some implementations the retrieval device isconstructed in a manner that results in a radial force being exerted bythe main body portion 853 that is greater than the radial force exertedby the distal portion 855 when the retrieval device 850 is deployedwithin a duct of a patient. To achieve this variation in a radial force,in some implementations the width dimension of the struts in the mainbody portion 853 of the retrieval device are cut to have a larger widthdimension of at least some or all of the struts in the distal portion855.

As shown in FIGS. 48A and 48B, in some implementations the strut densityin the distal segment 855 is further enhanced by the inclusion ofnon-linear struts 860 in at least some of the cell structures. In someimplementations the non-linear struts extend between the proximal end864 and distal end 866 of cell structures. In some implementations thenon-linear struts 860 extend between the proximal end 864 and distal end866 of cell structures with the non-linear strut 861 havingsubstantially the same length as the upper strut 861 and/or lower strut862 in the as-cut configuration. Such a construction enhances theability of the cell structure struts to nest resulting in a lowerachievable constrained diameter of the retrieval device. In someimplementations the non-linear struts 861 extend between the proximalend 864 and distal end 866 of cell structures with the upper, lower andnon-linear struts 860, 862 and 861, respectively, having substantiallythe same length in the as-cut configuration. So as not to greatly impactthe radial force produced in the distal segment 855, in someimplementations the non-linear struts 860 have a width dimension lessthan the width dimension of the upper and lower struts 861 and 862. Insome implementations the ratio of the width dimension of struts 860 andthe width dimension of each of the upper and lower struts 861 and 862,respectively, is between about 0.70 and 0.80. For example, according toone implementation each of the upper and lower struts, 361 and 362, havea width dimension of about 0.0035 inches while strut 360 has a widthdimension of about 0.0025 inches.

FIG. 49 illustrates a variation to the as-cut configuration shown inFIG. 48A. As shown in FIG. 49, the retrieval device 870 comprises aproximal distal portion 871, a main body portion 872 and a distalportion 873, the distal portion being shorter in length than thatdepicted in FIG. 48A.

While the above description contains many specifics, those specificsshould not be construed as limitations on the scope of the disclosure,but merely as exemplifications of preferred embodiments thereof. Forexample, dimensions other than those listed above are contemplated. Forexample, retrieval devices having expanded diameters of any wherebetween 1.0 and 100.0 millimeters and lengths of up to 5.0 to 10.0centimeters are contemplated. Moreover, it is appreciated that many ofthe features disclosed herein are interchangeable among the variousembodiments. Those skilled in the art will envision many other possiblevariations that are within the scope and spirit of the disclosure.Further, it is to be appreciated that the delivery of a vasculartreatment device of the embodiments disclosed herein is achievable withthe use of a catheter, a sheath or any other device that is capable ofcarrying the device with the expandable member in a compressed state tothe treatment site and which permits the subsequent deployment of theexpandable member at a vascular treatment site. The vascular treatmentsite may be (1) at the neck of an aneurysm for diverting flow and/orfacilitating the placement of coils or other like structures within thesack of an aneurysm, (2) at the site of an embolic obstruction with apurpose of removing the embolic obstruction, (3) at the site of astenosis with a purpose of dilating the stenosis to increase blood flowthrough the vascular, etc.

1.-35. (canceled)
 36. An embolic obstruction retrieval devicecomprising: an elongate self-expandable member expandable from a firstdelivery position to a second position, in the first delivery positionthe self-expandable member being in an unexpanded position and having afirst nominal diameter and in the second position the self-expandablemember being in a radially expanded position and having a second nominaldiameter greater than the first nominal diameter, the self-expandablemember comprising a plurality of cell structures, the self-expandablemember having a proximal end portion and an elongate cylindrical mainbody portion, the cell structures in the elongate cylindrical main bodyportion extending circumferentially around a longitudinal axis of theself-expandable member, the cell structures in the proximal end portionextending less than circumferentially around the longitudinal axis ofthe self-expandable member, the proximal end portion having a pluralityof outer-most cell structures that include outer-most wall segments thatform first and second rail segments that each extend from a position ator near a proximal-most end of the self-expandable member to a positionat or near the elongate cylindrical main body portion, a proximal-mostcell structure of the proximal end portion comprising first and secondouter struts that extend distally from a proximal antenna, when theself-expandable member is cut and laid flat on a surface at least aportion of each of the first and second outer struts comprise a straightsegment, each of the straight segments being coextensive with theproximal antenna, the proximal-most cell structure being a closedfour-sided structure when the self-expandable member is cut and laidflat on a surface, the closed four-sided structure comprising the firstouter strut, the second outer strut, a first inner strut and a secondinner strut, the first inner strut extending distally from the firstouter strut, the second inner strut extending distally from the secondouter strut, when the self-expandable member is cut and laid flat on asurface all or substantially all of the first and second inner strutsare curvilinear.
 37. The embolic obstruction retrieval device of claim36, wherein when the self-expandable member is cut and laid flat on asurface substantially the entire length of the first and second outerstruts are straight and all or substantially all of the first and secondinner struts are curvilinear.
 38. The embolic obstruction retrievaldevice of claim 36, wherein when the self-expandable member is cut andlaid flat on a surface all or substantially all of the first and secondinner struts are curvilinear, substantially all of the first outer strutis straight and only a portion of the second outer strut is straight.39. The embolic obstruction retrieval device of claim 36, wherein thecombined length of the first outer strut and the first inner strut issubstantially equal to the combined length of the second outer strut andsecond inner strut.
 40. The embolic obstruction retrieval device ofclaim 36, wherein when the self-expandable member is cut and laid flaton a surface all or substantially all of the first and second innerstruts are curvilinear, the combined length of the first outer strut andthe first inner strut being substantially equal to the combined lengthof the second outer strut and second inner strut.
 41. The embolicobstruction retrieval device of claim 36, wherein when theself-expandable member is cut and laid flat on a surface substantiallyall of the first and second outer struts are straight and all orsubstantially all of the first and second inner struts are curvilinear,the combined length of the first outer strut and the first inner strutbeing substantially equal to the combined length of the second outerstrut and second inner strut.
 42. The embolic obstruction retrievaldevice of claim 36, wherein when the self-expandable member is cut andlaid flat on a surface all or substantially all of the first and secondinner struts are curvilinear, substantially all of the first outer strutis straight and only a portion of the second outer strut is straight,the combined length of the first outer strut and the first inner strutbeing substantially equal to the combined length of the second outerstrut and second inner strut.
 43. The embolic obstruction retrievaldevice of claim 36, wherein the straight segment of the first outerstrut comprises a first proximal portion adjacent to the proximalantenna and the straight segment of the second outer strut comprises asecond proximal portion adjacent to the proximal antenna, each of thefirst and second proximal portions having a width dimension less thanthe remainder of their respective straight segments.
 44. The embolicobstruction retrieval device of claim 43, wherein the first and secondproximal portions comprise tapers.
 45. The embolic obstruction retrievaldevice of claim 36, wherein each of the first and second outer strutscomprise a proximal portion, a mid-portion and a distal portion, thefirst inner strut extending distally from the distal portion of thefirst outer strut, the second inner strut extending distally from thedistal portion of the second outer strut, when the self-expandablemember is cut and laid flat on a surface the mid-portion of the firstand second outer struts are straight and all or substantially all of thefirst and second inner struts are curvilinear.
 46. The embolicobstruction retrieval device of claim 45, wherein the proximal portionsof the first and second outer struts are situated adjacent to theproximal antenna, each of the proximal portions having a width dimensionless than the width dimension of the respective mid-portions.
 47. Theembolic obstruction retrieval device of claim 46, wherein the proximalportions comprise tapers which extend proximally from the proximal endsof the respective mid-portions.
 48. The embolic obstruction retrievaldevice of claim 46, wherein the distal portions of the first and secondouter struts have a width dimension less than the width dimension of therespective mid-portions.
 49. The embolic obstruction retrieval device ofclaim 48, wherein the proximal portions comprise tapers which extendproximally from the proximal ends of the respective mid-portions andwherein the distal portions comprise tapers which extend distally fromthe distal ends of the respective mid-portions.
 50. The embolicobstruction retrieval device of claim 36, further comprising a firstproximally extending elongate flexible wire connected to the proximalantenna.